diff --git a/changelog/unreleased/max-input-image.md b/changelog/unreleased/max-input-image.md
new file mode 100644
index 0000000000..595279d9c0
--- /dev/null
+++ b/changelog/unreleased/max-input-image.md
@@ -0,0 +1,5 @@
+Change: Define maximum input image dimensions when generating previews
+
+This is a general hardening change to limit processing time and resources of the thumbnailer.
+
+https://github.com/owncloud/ocis/pull/9035
diff --git a/services/thumbnails/pkg/command/server.go b/services/thumbnails/pkg/command/server.go
index 580e70e885..d62095dd28 100644
--- a/services/thumbnails/pkg/command/server.go
+++ b/services/thumbnails/pkg/command/server.go
@@ -26,10 +26,10 @@ func Server(cfg *config.Config) *cli.Command {
 		Name:     "server",
 		Usage:    fmt.Sprintf("start the %s service without runtime (unsupervised mode)", cfg.Service.Name),
 		Category: "server",
-		Before: func(c *cli.Context) error {
+		Before: func(_ *cli.Context) error {
 			return configlog.ReturnFatal(parser.ParseConfig(cfg))
 		},
-		Action: func(c *cli.Context) error {
+		Action: func(_ *cli.Context) error {
 			logger := logging.Configure(cfg.Service.Name, cfg.Log)
 
 			traceProvider, err := tracing.GetServiceTraceProvider(cfg.Tracing, cfg.Service.Name)
@@ -49,12 +49,12 @@ func Server(cfg *config.Config) *cli.Command {
 					}
 					return context.WithCancel(cfg.Context)
 				}()
-				metrics = metrics.New()
+				m = metrics.New()
 			)
 
 			defer cancel()
 
-			metrics.BuildInfo.WithLabelValues(version.GetString()).Set(1)
+			m.BuildInfo.WithLabelValues(version.GetString()).Set(1)
 
 			service := grpc.NewService(
 				grpc.Logger(logger),
@@ -63,7 +63,7 @@ func Server(cfg *config.Config) *cli.Command {
 				grpc.Name(cfg.Service.Name),
 				grpc.Namespace(cfg.GRPC.Namespace),
 				grpc.Address(cfg.GRPC.Addr),
-				grpc.Metrics(metrics),
+				grpc.Metrics(m),
 				grpc.TraceProvider(traceProvider),
 			)
 
@@ -95,7 +95,7 @@ func Server(cfg *config.Config) *cli.Command {
 				http.Logger(logger),
 				http.Context(ctx),
 				http.Config(cfg),
-				http.Metrics(metrics),
+				http.Metrics(m),
 				http.Namespace(cfg.HTTP.Namespace),
 				http.TraceProvider(traceProvider),
 			)
diff --git a/services/thumbnails/pkg/command/version.go b/services/thumbnails/pkg/command/version.go
index b52381f04a..4d7377b378 100644
--- a/services/thumbnails/pkg/command/version.go
+++ b/services/thumbnails/pkg/command/version.go
@@ -18,7 +18,7 @@ func Version(cfg *config.Config) *cli.Command {
 		Name:     "version",
 		Usage:    "print the version of this binary and the running service instances",
 		Category: "info",
-		Action: func(c *cli.Context) error {
+		Action: func(_ *cli.Context) error {
 			fmt.Println("Version: " + version.GetString())
 			fmt.Printf("Compiled: %s\n", version.Compiled())
 			fmt.Println("")
diff --git a/services/thumbnails/pkg/config/config.go b/services/thumbnails/pkg/config/config.go
index 85e882a29e..59d2032cf8 100644
--- a/services/thumbnails/pkg/config/config.go
+++ b/services/thumbnails/pkg/config/config.go
@@ -44,4 +44,6 @@ type Thumbnail struct {
 	FontMapFile         string            `yaml:"font_map_file" env:"THUMBNAILS_TXT_FONTMAP_FILE" desc:"The path to a font file for txt thumbnails." introductionVersion:"pre5.0"`
 	TransferSecret      string            `yaml:"transfer_secret" env:"THUMBNAILS_TRANSFER_TOKEN" desc:"The secret to sign JWT to download the actual thumbnail file." introductionVersion:"pre5.0"`
 	DataEndpoint        string            `yaml:"data_endpoint" env:"THUMBNAILS_DATA_ENDPOINT" desc:"The HTTP endpoint where the actual thumbnail file can be downloaded." introductionVersion:"pre5.0"`
+	MaxInputWidth       int               `yaml:"max_input_width" env:"THUMBNAILS_MAX_INPUT_WIDTH" desc:"The maximum width of an input image which is being processed." introductionVersion:"6.0"`
+	MaxInputHeight      int               `yaml:"max_input_height" env:"THUMBNAILS_MAX_INPUT_HEIGHT" desc:"The maximum height of an input image which is being processed." introductionVersion:"6.0"`
 }
diff --git a/services/thumbnails/pkg/config/defaults/defaultconfig.go b/services/thumbnails/pkg/config/defaults/defaultconfig.go
index 84c1011ef6..a0465a7efc 100644
--- a/services/thumbnails/pkg/config/defaults/defaultconfig.go
+++ b/services/thumbnails/pkg/config/defaults/defaultconfig.go
@@ -48,6 +48,8 @@ func DefaultConfig() *config.Config {
 			RevaGateway:         shared.DefaultRevaConfig().Address,
 			CS3AllowInsecure:    false,
 			DataEndpoint:        "http://127.0.0.1:9186/thumbnails/data",
+			MaxInputWidth:       7680,
+			MaxInputHeight:      4320,
 		},
 	}
 }
diff --git a/services/thumbnails/pkg/config/parser/parse.go b/services/thumbnails/pkg/config/parser/parse.go
index 6334261084..4ec11019dd 100644
--- a/services/thumbnails/pkg/config/parser/parse.go
+++ b/services/thumbnails/pkg/config/parser/parse.go
@@ -33,6 +33,7 @@ func ParseConfig(cfg *config.Config) error {
 	return Validate(cfg)
 }
 
-func Validate(cfg *config.Config) error {
+// Validate can validate the configuration
+func Validate(_ *config.Config) error {
 	return nil
 }
diff --git a/services/thumbnails/pkg/errors/error.go b/services/thumbnails/pkg/errors/error.go
new file mode 100644
index 0000000000..e8bbe30889
--- /dev/null
+++ b/services/thumbnails/pkg/errors/error.go
@@ -0,0 +1,18 @@
+package errors
+
+import "errors"
+
+var (
+	// ErrImageTooLarge defines an error when an input image is too large
+	ErrImageTooLarge = errors.New("thumbnails: image is too large")
+	// ErrInvalidType represents the error when a type can't be encoded.
+	ErrInvalidType = errors.New("thumbnails: can't encode this type")
+	// ErrNoEncoderForType represents the error when an encoder couldn't be found for a type.
+	ErrNoEncoderForType = errors.New("thumbnails: no encoder for this type found")
+	// ErrNoImageFromAudioFile defines an error when an image cannot be extracted from an audio file
+	ErrNoImageFromAudioFile = errors.New("thumbnails: could not extract image from audio file")
+	// ErrNoConverterForExtractedImageFromAudioFile defines an error when the extracted image from an audio file could not be converted
+	ErrNoConverterForExtractedImageFromAudioFile = errors.New("thumbnails: could not find converter for image extracted from audio file")
+	// ErrCS3AuthorizationMissing defines an error when the CS3 authorization is missing
+	ErrCS3AuthorizationMissing = errors.New("thumbnails: cs3source - authorization missing")
+)
diff --git a/services/thumbnails/pkg/preprocessor/fontloader.go b/services/thumbnails/pkg/preprocessor/fontloader.go
index 672e62593c..69f979e61b 100644
--- a/services/thumbnails/pkg/preprocessor/fontloader.go
+++ b/services/thumbnails/pkg/preprocessor/fontloader.go
@@ -25,28 +25,28 @@ type FontMap struct {
 	DefaultFont string            `json:"defaultFont"`
 }
 
-// It contains the location of the loaded file (in FLoc) and the FontMap loaded
+// FontMapData contains the location of the loaded file (in FLoc) and the FontMap loaded
 // from the file
 type FontMapData struct {
 	FMap *FontMap
 	FLoc string
 }
 
-// It contains the location of the font used, and the loaded face (font.Face)
+// LoadedFace contains the location of the font used, and the loaded face (font.Face)
 // ready to be used
 type LoadedFace struct {
 	FontFile string
 	Face     font.Face
 }
 
-// Represents a FontLoader. Use the "NewFontLoader" to get a instance
+// FontLoader represents a FontLoader. Use the "NewFontLoader" to get a instance
 type FontLoader struct {
 	faceCache   sync.Cache
 	fontMapData *FontMapData
 	faceOpts    *opentype.FaceOptions
 }
 
-// Create a new FontLoader based on the fontMapFile. The FaceOptions will
+// NewFontLoader creates a new FontLoader based on the fontMapFile. The FaceOptions will
 // be the same for all the font loaded by this instance.
 // Note that only the fonts described in the fontMapFile will be used.
 //
@@ -92,7 +92,7 @@ func NewFontLoader(fontMapFile string, faceOpts *opentype.FaceOptions) (*FontLoa
 	}, nil
 }
 
-// Load and return the font face to be used for that script according to the
+// LoadFaceForScript loads and returns the font face to be used for that script according to the
 // FontMap set when the FontLoader was created. If the script doesn't have
 // an associated font, a default font will be used. Note that the default font
 // might not be able to handle properly the script
@@ -146,14 +146,17 @@ func (fl *FontLoader) LoadFaceForScript(script string) (*LoadedFace, error) {
 	return loadedFace, nil
 }
 
+// GetFaceOptSize returns face opt size
 func (fl *FontLoader) GetFaceOptSize() float64 {
 	return fl.faceOpts.Size
 }
 
+// GetFaceOptDPI returns face opt DPI
 func (fl *FontLoader) GetFaceOptDPI() float64 {
 	return fl.faceOpts.DPI
 }
 
+// GetScriptList returns script list
 func (fl *FontLoader) GetScriptList() []string {
 	fontMap := fl.fontMapData.FMap.FontMap
 
diff --git a/services/thumbnails/pkg/preprocessor/preprocessor.go b/services/thumbnails/pkg/preprocessor/preprocessor.go
index d8addd3a70..4254c1a68b 100644
--- a/services/thumbnails/pkg/preprocessor/preprocessor.go
+++ b/services/thumbnails/pkg/preprocessor/preprocessor.go
@@ -19,6 +19,7 @@ import (
 	"golang.org/x/image/math/fixed"
 
 	"github.com/dhowden/tag"
+	thumbnailerErrors "github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
 )
 
 // FileConverter is the interface for the file converter
@@ -98,12 +99,12 @@ func (i AudioDecoder) Convert(r io.Reader) (interface{}, error) {
 
 	picture := m.Picture()
 	if picture == nil {
-		return nil, errors.New(`could not extract image from audio file`)
+		return nil, thumbnailerErrors.ErrNoImageFromAudioFile
 	}
 
 	converter := ForType(picture.MIMEType, nil)
 	if converter == nil {
-		return nil, errors.New(`could not find converter for image extraced from audio file`)
+		return nil, thumbnailerErrors.ErrNoConverterForExtractedImageFromAudioFile
 	}
 
 	return converter.Convert(bytes.NewReader(picture.Data))
@@ -259,7 +260,7 @@ func ForType(mimeType string, opts map[string]interface{}) FileConverter {
 
 		fontLoader, err := NewFontLoader(fontFileMap, fontFaceOpts)
 		if err != nil {
-			// if couldn't create the FontLoader with the specified fontFileMap,
+			// if it couldn't create the FontLoader with the specified fontFileMap,
 			// try to use the default font
 			fontLoader, _ = NewFontLoader("", fontFaceOpts)
 		}
diff --git a/services/thumbnails/pkg/server/debug/server.go b/services/thumbnails/pkg/server/debug/server.go
index 55ad0121d4..0f912967d8 100644
--- a/services/thumbnails/pkg/server/debug/server.go
+++ b/services/thumbnails/pkg/server/debug/server.go
@@ -27,8 +27,8 @@ func Server(opts ...Option) (*http.Server, error) {
 }
 
 // health implements the health check.
-func health(cfg *config.Config) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
+func health(_ *config.Config) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, _ *http.Request) {
 		w.Header().Set("Content-Type", "text/plain")
 		w.WriteHeader(http.StatusOK)
 
@@ -43,8 +43,8 @@ func health(cfg *config.Config) func(http.ResponseWriter, *http.Request) {
 }
 
 // ready implements the ready check.
-func ready(cfg *config.Config) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
+func ready(_ *config.Config) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, _ *http.Request) {
 		w.Header().Set("Content-Type", "text/plain")
 		w.WriteHeader(http.StatusOK)
 
diff --git a/services/thumbnails/pkg/server/http/option.go b/services/thumbnails/pkg/server/http/option.go
index b77014b159..6bbf4627be 100644
--- a/services/thumbnails/pkg/server/http/option.go
+++ b/services/thumbnails/pkg/server/http/option.go
@@ -8,6 +8,7 @@ import (
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/metrics"
 	"github.com/urfave/cli/v2"
 	"go.opentelemetry.io/otel/trace"
+	"go.opentelemetry.io/otel/trace/noop"
 )
 
 // Option defines a single option function.
@@ -76,7 +77,7 @@ func TraceProvider(traceProvider trace.TracerProvider) Option {
 		if traceProvider != nil {
 			o.TraceProvider = traceProvider
 		} else {
-			o.TraceProvider = trace.NewNoopTracerProvider()
+			o.TraceProvider = noop.NewTracerProvider()
 		}
 	}
 }
diff --git a/services/thumbnails/pkg/service/grpc/v0/decorators/base.go b/services/thumbnails/pkg/service/grpc/v0/decorators/base.go
index c43d393dec..5a1f6d3c0d 100644
--- a/services/thumbnails/pkg/service/grpc/v0/decorators/base.go
+++ b/services/thumbnails/pkg/service/grpc/v0/decorators/base.go
@@ -6,7 +6,7 @@ import (
 	thumbnailssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/thumbnails/v0"
 )
 
-// Interface acting as facade, holding all the interfaces that this
+// DecoratedService is an interface acting as facade, holding all the interfaces that this
 // thumbnails microservice is expecting to implement.
 // For now, only the thumbnailssvc.ThumbnailServiceHandler is present,
 // but a future configsvc.ConfigServiceHandler is expected to be added here
@@ -17,7 +17,7 @@ type DecoratedService interface {
 	thumbnailssvc.ThumbnailServiceHandler
 }
 
-// Base type to implement the decorators. It will provide a basic implementation
+// Decorator is the base type to implement the decorators. It will provide a basic implementation
 // by delegating to the decoratedService
 //
 // Expected implementations will be like:
@@ -43,7 +43,7 @@ type Decorator struct {
 	next DecoratedService
 }
 
-// Base implementation for the GetThumbnail (for the thumbnailssvc).
+// GetThumbnail is the base implementation for the thumbnailssvc.GetThumbnail.
 // It will just delegate to the underlying decoratedService
 //
 // Your custom decorator is expected to overwrite this function,
diff --git a/services/thumbnails/pkg/service/grpc/v0/decorators/logging.go b/services/thumbnails/pkg/service/grpc/v0/decorators/logging.go
index e8174d40ee..c998af1b2d 100644
--- a/services/thumbnails/pkg/service/grpc/v0/decorators/logging.go
+++ b/services/thumbnails/pkg/service/grpc/v0/decorators/logging.go
@@ -34,11 +34,11 @@ func (l logging) GetThumbnail(ctx context.Context, req *thumbnailssvc.GetThumbna
 		Logger()
 
 	if err != nil {
-		merror := merrors.FromError(err)
-		switch merror.Code {
+		fromError := merrors.FromError(err)
+		switch fromError.GetCode() {
 		case http.StatusNotFound:
 			logger.Debug().
-				Str("error_detail", merror.Detail).
+				Str("error_detail", fromError.GetDetail()).
 				Msg("no thumbnail found")
 		default:
 			logger.Warn().
diff --git a/services/thumbnails/pkg/service/grpc/v0/decorators/tracing.go b/services/thumbnails/pkg/service/grpc/v0/decorators/tracing.go
index f34166e3e6..ba77846c0d 100644
--- a/services/thumbnails/pkg/service/grpc/v0/decorators/tracing.go
+++ b/services/thumbnails/pkg/service/grpc/v0/decorators/tracing.go
@@ -35,10 +35,10 @@ func (t tracing) GetThumbnail(ctx context.Context, req *thumbnailssvc.GetThumbna
 		defer span.End()
 
 		span.SetAttributes(
-			attribute.KeyValue{Key: "filepath", Value: attribute.StringValue(req.Filepath)},
-			attribute.KeyValue{Key: "thumbnail_type", Value: attribute.StringValue(req.ThumbnailType.String())},
-			attribute.KeyValue{Key: "width", Value: attribute.IntValue(int(req.Width))},
-			attribute.KeyValue{Key: "height", Value: attribute.IntValue(int(req.Height))},
+			attribute.KeyValue{Key: "filepath", Value: attribute.StringValue(req.GetFilepath())},
+			attribute.KeyValue{Key: "thumbnail_type", Value: attribute.StringValue(req.GetThumbnailType().String())},
+			attribute.KeyValue{Key: "width", Value: attribute.IntValue(int(req.GetWidth()))},
+			attribute.KeyValue{Key: "height", Value: attribute.IntValue(int(req.GetHeight()))},
 		)
 	}
 
diff --git a/services/thumbnails/pkg/service/grpc/v0/option.go b/services/thumbnails/pkg/service/grpc/v0/option.go
index 00cf0eeab3..07c1556e41 100644
--- a/services/thumbnails/pkg/service/grpc/v0/option.go
+++ b/services/thumbnails/pkg/service/grpc/v0/option.go
@@ -50,13 +50,6 @@ func Config(val *config.Config) Option {
 	}
 }
 
-// Middleware provides a function to set the middleware option.
-func Middleware(val ...func(http.Handler) http.Handler) Option {
-	return func(o *Options) {
-		o.Middleware = val
-	}
-}
-
 // ThumbnailStorage provides a function to set the thumbnail storage option.
 func ThumbnailStorage(val storage.Storage) Option {
 	return func(o *Options) {
diff --git a/services/thumbnails/pkg/service/grpc/v0/service.go b/services/thumbnails/pkg/service/grpc/v0/service.go
index 156b46e0ef..5982b1ca40 100644
--- a/services/thumbnails/pkg/service/grpc/v0/service.go
+++ b/services/thumbnails/pkg/service/grpc/v0/service.go
@@ -43,6 +43,8 @@ func NewService(opts ...Option) decorators.DecoratedService {
 			resolutions,
 			options.ThumbnailStorage,
 			logger,
+			options.Config.Thumbnail.MaxInputWidth,
+			options.Config.Thumbnail.MaxInputHeight,
 		),
 		webdavSource: options.ImageSource,
 		cs3Source:    options.CS3Source,
@@ -116,7 +118,7 @@ func (g Thumbnail) GetThumbnail(ctx context.Context, req *thumbnailssvc.GetThumb
 
 func (g Thumbnail) handleCS3Source(ctx context.Context, req *thumbnailssvc.GetThumbnailRequest) (string, error) {
 	src := req.GetCs3Source()
-	sRes, err := g.stat(src.Path, src.Authorization)
+	sRes, err := g.stat(src.GetPath(), src.GetAuthorization())
 	if err != nil {
 		return "", err
 	}
@@ -125,7 +127,7 @@ func (g Thumbnail) handleCS3Source(ctx context.Context, req *thumbnailssvc.GetTh
 	if tType == "" {
 		tType = req.GetThumbnailType().String()
 	}
-	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum(), req.Processor)
+	tr, err := thumbnail.PrepareRequest(int(req.GetWidth()), int(req.GetHeight()), tType, sRes.GetInfo().GetChecksum().GetSum(), req.GetProcessor())
 	if err != nil {
 		return "", merrors.BadRequest(g.serviceID, err.Error())
 	}
@@ -134,12 +136,12 @@ func (g Thumbnail) handleCS3Source(ctx context.Context, req *thumbnailssvc.GetTh
 		return key, nil
 	}
 
-	ctx = imgsource.ContextSetAuthorization(ctx, src.Authorization)
-	r, err := g.cs3Source.Get(ctx, src.Path)
+	ctx = imgsource.ContextSetAuthorization(ctx, src.GetAuthorization())
+	r, err := g.cs3Source.Get(ctx, src.GetPath())
 	if err != nil {
 		return "", merrors.InternalServerError(g.serviceID, "could not get image from source: %s", err.Error())
 	}
-	defer r.Close() // nolint:errcheck
+	defer r.Close()
 	ppOpts := map[string]interface{}{
 		"fontFileMap": g.preprocessorOpts.TxtFontFileMap,
 	}
@@ -158,13 +160,13 @@ func (g Thumbnail) handleCS3Source(ctx context.Context, req *thumbnailssvc.GetTh
 
 func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.GetThumbnailRequest) (string, error) {
 	src := req.GetWebdavSource()
-	imgURL, err := url.Parse(src.Url)
+	imgURL, err := url.Parse(src.GetUrl())
 	if err != nil {
 		return "", errors.Wrap(err, "source url is invalid")
 	}
 
 	var auth, statPath string
-	if src.IsPublicLink {
+	if src.GetIsPublicLink() {
 		q := imgURL.Query()
 		var rsp *gateway.AuthenticateResponse
 		client, err := g.selector.Next()
@@ -177,13 +179,13 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 			exp := q.Get("expiration")
 			rsp, err = client.Authenticate(ctx, &gateway.AuthenticateRequest{
 				Type:         "publicshares",
-				ClientId:     src.PublicLinkToken,
+				ClientId:     src.GetPublicLinkToken(),
 				ClientSecret: strings.Join([]string{"signature", sig, exp}, "|"),
 			})
 		} else {
 			rsp, err = client.Authenticate(ctx, &gateway.AuthenticateRequest{
 				Type:     "publicshares",
-				ClientId: src.PublicLinkToken,
+				ClientId: src.GetPublicLinkToken(),
 				// We pass an empty password because we expect non pre-signed public links
 				// to not be password protected
 				ClientSecret: "password|",
@@ -193,11 +195,11 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 		if err != nil {
 			return "", merrors.InternalServerError(g.serviceID, "could not authenticate: %s", err.Error())
 		}
-		auth = rsp.Token
-		statPath = path.Join("/public", src.PublicLinkToken, req.Filepath)
+		auth = rsp.GetToken()
+		statPath = path.Join("/public", src.GetPublicLinkToken(), req.GetFilepath())
 	} else {
-		auth = src.RevaAuthorization
-		statPath = req.Filepath
+		auth = src.GetRevaAuthorization()
+		statPath = req.GetFilepath()
 	}
 	sRes, err := g.stat(statPath, auth)
 	if err != nil {
@@ -208,7 +210,7 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 	if tType == "" {
 		tType = req.GetThumbnailType().String()
 	}
-	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum(), req.Processor)
+	tr, err := thumbnail.PrepareRequest(int(req.GetWidth()), int(req.GetHeight()), tType, sRes.GetInfo().GetChecksum().GetSum(), req.GetProcessor())
 	if err != nil {
 		return "", merrors.BadRequest(g.serviceID, err.Error())
 	}
@@ -217,8 +219,8 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 		return key, nil
 	}
 
-	if src.WebdavAuthorization != "" {
-		ctx = imgsource.ContextSetAuthorization(ctx, src.WebdavAuthorization)
+	if src.GetWebdavAuthorization() != "" {
+		ctx = imgsource.ContextSetAuthorization(ctx, src.GetWebdavAuthorization())
 	}
 
 	// add signature and expiration to webdav url
@@ -232,7 +234,7 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 	if err != nil {
 		return "", merrors.InternalServerError(g.serviceID, "could not get image from source: %s", err.Error())
 	}
-	defer r.Close() // nolint:errcheck
+	defer r.Close()
 	ppOpts := map[string]interface{}{
 		"fontFileMap": g.preprocessorOpts.TxtFontFileMap,
 	}
@@ -272,16 +274,16 @@ func (g Thumbnail) stat(path, auth string) (*provider.StatResponse, error) {
 		return nil, merrors.InternalServerError(g.serviceID, "could not stat file: %s", err.Error())
 	}
 
-	if rsp.Status.Code != rpc.Code_CODE_OK {
-		switch rsp.Status.Code {
+	if rsp.GetStatus().GetCode() != rpc.Code_CODE_OK {
+		switch rsp.GetStatus().GetCode() {
 		case rpc.Code_CODE_NOT_FOUND:
-			return nil, merrors.NotFound(g.serviceID, "could not stat file: %s", rsp.Status.Message)
+			return nil, merrors.NotFound(g.serviceID, "could not stat file: %s", rsp.GetStatus().GetMessage())
 		default:
-			g.logger.Error().Str("status_message", rsp.Status.Message).Str("path", path).Msg("could not stat file")
-			return nil, merrors.InternalServerError(g.serviceID, "could not stat file: %s", rsp.Status.Message)
+			g.logger.Error().Str("status_message", rsp.GetStatus().GetMessage()).Str("path", path).Msg("could not stat file")
+			return nil, merrors.InternalServerError(g.serviceID, "could not stat file: %s", rsp.GetStatus().GetMessage())
 		}
 	}
-	if rsp.Info.Type != provider.ResourceType_RESOURCE_TYPE_FILE {
+	if rsp.GetInfo().GetType() != provider.ResourceType_RESOURCE_TYPE_FILE {
 		return nil, merrors.BadRequest(g.serviceID, "Unsupported file type")
 	}
 	if utils.ReadPlainFromOpaque(rsp.GetInfo().GetOpaque(), "status") == "processing" {
@@ -292,11 +294,11 @@ func (g Thumbnail) stat(path, auth string) (*provider.StatResponse, error) {
 			Status: http.StatusText(http.StatusTooEarly),
 		}
 	}
-	if rsp.Info.GetChecksum().GetSum() == "" {
+	if rsp.GetInfo().GetChecksum().GetSum() == "" {
 		g.logger.Error().Msg("resource info is missing checksum")
 		return nil, merrors.NotFound(g.serviceID, "resource info is missing a checksum")
 	}
-	if !thumbnail.IsMimeTypeSupported(rsp.Info.MimeType) {
+	if !thumbnail.IsMimeTypeSupported(rsp.GetInfo().GetMimeType()) {
 		return nil, merrors.NotFound(g.serviceID, "Unsupported file type")
 	}
 	return rsp, nil
diff --git a/services/thumbnails/pkg/service/http/v0/option.go b/services/thumbnails/pkg/service/http/v0/option.go
index aa630843ec..d7ba389e3e 100644
--- a/services/thumbnails/pkg/service/http/v0/option.go
+++ b/services/thumbnails/pkg/service/http/v0/option.go
@@ -59,14 +59,3 @@ func ThumbnailStorage(storage storage.Storage) Option {
 		o.ThumbnailStorage = storage
 	}
 }
-
-// TraceProvider provides a function to configure the trace provider
-func TraceProvider(traceProvider trace.TracerProvider) Option {
-	return func(o *Options) {
-		if traceProvider != nil {
-			o.TraceProvider = traceProvider
-		} else {
-			o.TraceProvider = trace.NewNoopTracerProvider()
-		}
-	}
-}
diff --git a/services/thumbnails/pkg/service/http/v0/service.go b/services/thumbnails/pkg/service/http/v0/service.go
index 8e36a3727d..7207507a7e 100644
--- a/services/thumbnails/pkg/service/http/v0/service.go
+++ b/services/thumbnails/pkg/service/http/v0/service.go
@@ -25,8 +25,8 @@ const (
 
 // Service defines the service handlers.
 type Service interface {
-	ServeHTTP(http.ResponseWriter, *http.Request)
-	GetThumbnail(http.ResponseWriter, *http.Request)
+	ServeHTTP(w http.ResponseWriter, r *http.Request)
+	GetThumbnail(w http.ResponseWriter, r *http.Request)
 }
 
 // NewService returns a service implementation for Service.
@@ -58,6 +58,8 @@ func NewService(opts ...Option) Service {
 			resolutions,
 			options.ThumbnailStorage,
 			logger,
+			options.Config.Thumbnail.MaxInputWidth,
+			options.Config.Thumbnail.MaxInputHeight,
 		),
 	}
 
@@ -66,7 +68,7 @@ func NewService(opts ...Option) Service {
 		r.Get("/data", svc.GetThumbnail)
 	})
 
-	_ = chi.Walk(m, func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error {
+	_ = chi.Walk(m, func(method string, route string, _ http.Handler, middlewares ...func(http.Handler) http.Handler) error {
 		options.Logger.Debug().Str("method", method).Str("route", route).Int("middlewares", len(middlewares)).Msg("serving endpoint")
 		return nil
 	})
@@ -92,7 +94,7 @@ func (s Thumbnails) GetThumbnail(w http.ResponseWriter, r *http.Request) {
 	logger := s.logger.SubloggerWithRequestID(r.Context())
 	key := r.Context().Value(keyContextKey).(string)
 
-	thumbnail, err := s.manager.GetThumbnail(key)
+	thumbnailBytes, err := s.manager.GetThumbnail(key)
 	if err != nil {
 		logger.Debug().
 			Err(err).
@@ -103,8 +105,8 @@ func (s Thumbnails) GetThumbnail(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.WriteHeader(http.StatusOK)
-	w.Header().Set("Content-Length", strconv.Itoa(len(thumbnail)))
-	if _, err = w.Write(thumbnail); err != nil {
+	w.Header().Set("Content-Length", strconv.Itoa(len(thumbnailBytes)))
+	if _, err = w.Write(thumbnailBytes); err != nil {
 		logger.Error().
 			Err(err).
 			Str("key", key).
@@ -112,6 +114,7 @@ func (s Thumbnails) GetThumbnail(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// TransferTokenValidator validates a transfer token
 func (s Thumbnails) TransferTokenValidator(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		logger := s.logger.SubloggerWithRequestID(r.Context())
diff --git a/services/thumbnails/pkg/service/jwt/jwt.go b/services/thumbnails/pkg/service/jwt/jwt.go
index bbe46bb94d..86e1ff02cc 100644
--- a/services/thumbnails/pkg/service/jwt/jwt.go
+++ b/services/thumbnails/pkg/service/jwt/jwt.go
@@ -2,6 +2,7 @@ package jwt
 
 import "github.com/golang-jwt/jwt/v4"
 
+// ThumbnailClaims defines the claims for thumb-nailing
 type ThumbnailClaims struct {
 	jwt.RegisteredClaims
 	Key string `json:"key"`
diff --git a/services/thumbnails/pkg/thumbnail/encoding.go b/services/thumbnails/pkg/thumbnail/encoding.go
index 65b5b17373..2cf22ba360 100644
--- a/services/thumbnails/pkg/thumbnail/encoding.go
+++ b/services/thumbnails/pkg/thumbnail/encoding.go
@@ -1,13 +1,14 @@
 package thumbnail
 
 import (
-	"errors"
 	"image"
 	"image/gif"
 	"image/jpeg"
 	"image/png"
 	"io"
 	"strings"
+
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
 )
 
 const (
@@ -18,17 +19,10 @@ const (
 	typeGgs  = "ggs"
 )
 
-var (
-	// ErrInvalidType represents the error when a type can't be encoded.
-	ErrInvalidType = errors.New("can't encode this type")
-	// ErrNoEncoderForType represents the error when an encoder couldn't be found for a type.
-	ErrNoEncoderForType = errors.New("no encoder for this type found")
-)
-
 // Encoder encodes the thumbnail to a specific format.
 type Encoder interface {
 	// Encode encodes the image to a format.
-	Encode(io.Writer, interface{}) error
+	Encode(w io.Writer, img interface{}) error
 	// Types returns the formats suffixes.
 	Types() []string
 	// MimeType returns the mimetype used by the encoder.
@@ -42,7 +36,7 @@ type PngEncoder struct{}
 func (e PngEncoder) Encode(w io.Writer, img interface{}) error {
 	m, ok := img.(image.Image)
 	if !ok {
-		return ErrInvalidType
+		return errors.ErrInvalidType
 	}
 	return png.Encode(w, m)
 }
@@ -57,14 +51,14 @@ func (e PngEncoder) MimeType() string {
 	return "image/png"
 }
 
-// JpegEncoder encodes to jpg.
+// JpegEncoder encodes to jpg
 type JpegEncoder struct{}
 
 // Encode encodes to jpg
 func (e JpegEncoder) Encode(w io.Writer, img interface{}) error {
 	m, ok := img.(image.Image)
 	if !ok {
-		return ErrInvalidType
+		return errors.ErrInvalidType
 	}
 	return jpeg.Encode(w, m, nil)
 }
@@ -79,17 +73,19 @@ func (e JpegEncoder) MimeType() string {
 	return "image/jpeg"
 }
 
+// GifEncoder encodes to gif
 type GifEncoder struct{}
 
 // Encode encodes the image to a gif format
 func (e GifEncoder) Encode(w io.Writer, img interface{}) error {
 	g, ok := img.(*gif.GIF)
 	if !ok {
-		return ErrInvalidType
+		return errors.ErrInvalidType
 	}
 	return gif.EncodeAll(w, g)
 }
 
+// Types returns the supported types of the GifEncoder
 func (e GifEncoder) Types() []string {
 	return []string{typeGif}
 }
@@ -110,7 +106,7 @@ func EncoderForType(fileType string) (Encoder, error) {
 	case typeGif:
 		return GifEncoder{}, nil
 	default:
-		return nil, ErrNoEncoderForType
+		return nil, errors.ErrNoEncoderForType
 	}
 }
 
diff --git a/services/thumbnails/pkg/thumbnail/generator.go b/services/thumbnails/pkg/thumbnail/generator.go
index 80796ad7ce..177aad17a4 100644
--- a/services/thumbnails/pkg/thumbnail/generator.go
+++ b/services/thumbnails/pkg/thumbnail/generator.go
@@ -8,11 +8,12 @@ import (
 	"strings"
 
 	"github.com/kovidgoyal/imaging"
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
 )
 
 // Generator generates a web friendly file version.
 type Generator interface {
-	Generate(image.Rectangle, interface{}, Processor) (interface{}, error)
+	Generate(size image.Rectangle, img interface{}, processor Processor) (interface{}, error)
 }
 
 // SimpleGenerator is the default image generator and is used for all image types expect gif.
@@ -22,7 +23,7 @@ type SimpleGenerator struct{}
 func (g SimpleGenerator) Generate(size image.Rectangle, img interface{}, processor Processor) (interface{}, error) {
 	m, ok := img.(image.Image)
 	if !ok {
-		return nil, ErrInvalidType
+		return nil, errors.ErrInvalidType
 	}
 
 	return processor.Process(m, size.Dx(), size.Dy(), imaging.Lanczos), nil
@@ -37,7 +38,7 @@ func (g GifGenerator) Generate(size image.Rectangle, img interface{}, processor
 
 	m, ok := img.(*gif.GIF)
 	if !ok {
-		return nil, ErrInvalidType
+		return nil, errors.ErrInvalidType
 	}
 	// Create a new RGBA image to hold the incremental frames.
 	srcX, srcY := m.Config.Width, m.Config.Height
@@ -80,6 +81,6 @@ func GeneratorForType(fileType string) (Generator, error) {
 	case typeGif:
 		return GifGenerator{}, nil
 	default:
-		return nil, ErrNoEncoderForType
+		return nil, errors.ErrNoEncoderForType
 	}
 }
diff --git a/services/thumbnails/pkg/thumbnail/imgsource/cs3.go b/services/thumbnails/pkg/thumbnail/imgsource/cs3.go
index d17648e5f3..082ed60b0c 100644
--- a/services/thumbnails/pkg/thumbnail/imgsource/cs3.go
+++ b/services/thumbnails/pkg/thumbnail/imgsource/cs3.go
@@ -15,13 +15,13 @@ import (
 	"github.com/cs3org/reva/v2/pkg/rhttp"
 	"github.com/cs3org/reva/v2/pkg/storagespace"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/config"
-	"github.com/pkg/errors"
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
 	"google.golang.org/grpc/metadata"
 )
 
 const (
-	// "github.com/cs3org/reva/v2/internal/http/services/datagateway" is internal so we redeclare it here
 	// TokenTransportHeader holds the header key for the reva transfer token
+	// "github.com/cs3org/reva/v2/internal/http/services/datagateway" is internal so we redeclare it here
 	TokenTransportHeader = "X-Reva-Transfer"
 )
 
@@ -44,7 +44,7 @@ func NewCS3Source(cfg config.Thumbnail, gatewaySelector pool.Selectable[gateway.
 func (s CS3) Get(ctx context.Context, path string) (io.ReadCloser, error) {
 	auth, ok := ContextGetAuthorization(ctx)
 	if !ok {
-		return nil, errors.New("cs3source: authorization missing")
+		return nil, errors.ErrCS3AuthorizationMissing
 	}
 	ref, err := storagespace.ParseReference(path)
 	if err != nil {
@@ -66,18 +66,18 @@ func (s CS3) Get(ctx context.Context, path string) (io.ReadCloser, error) {
 		return nil, err
 	}
 
-	if rsp.Status.Code != rpc.Code_CODE_OK {
-		return nil, fmt.Errorf("could not load image: %s", rsp.Status.Message)
+	if rsp.GetStatus().GetCode() != rpc.Code_CODE_OK {
+		return nil, fmt.Errorf("could not load image: %s", rsp.GetStatus().GetMessage())
 	}
 	var ep, tk string
-	for _, p := range rsp.Protocols {
-		if p.Protocol == "spaces" {
-			ep, tk = p.DownloadEndpoint, p.Token
+	for _, p := range rsp.GetProtocols() {
+		if p.GetProtocol() == "spaces" {
+			ep, tk = p.GetDownloadEndpoint(), p.GetToken()
 			break
 		}
 	}
-	if (ep == "" || tk == "") && len(rsp.Protocols) > 0 {
-		ep, tk = rsp.Protocols[0].DownloadEndpoint, rsp.Protocols[0].Token
+	if (ep == "" || tk == "") && len(rsp.GetProtocols()) > 0 {
+		ep, tk = rsp.GetProtocols()[0].GetDownloadEndpoint(), rsp.GetProtocols()[0].GetToken()
 	}
 
 	httpReq, err := rhttp.NewRequest(ctx, "GET", ep, nil)
@@ -93,7 +93,7 @@ func (s CS3) Get(ctx context.Context, path string) (io.ReadCloser, error) {
 	}
 	client := &http.Client{}
 
-	resp, err := client.Do(httpReq) // nolint:bodyclose
+	resp, err := client.Do(httpReq)
 	if err != nil {
 		return nil, err
 	}
diff --git a/services/thumbnails/pkg/thumbnail/imgsource/webdav.go b/services/thumbnails/pkg/thumbnail/imgsource/webdav.go
index 6e02bc0465..9dda9dd8a1 100644
--- a/services/thumbnails/pkg/thumbnail/imgsource/webdav.go
+++ b/services/thumbnails/pkg/thumbnail/imgsource/webdav.go
@@ -44,7 +44,7 @@ func (s WebDav) Get(ctx context.Context, url string) (io.ReadCloser, error) {
 	}
 
 	client := &http.Client{}
-	resp, err := client.Do(req) // nolint:bodyclose
+	resp, err := client.Do(req)
 	if err != nil {
 		return nil, errors.Wrapf(err, `could not get the image "%s"`, url)
 	}
diff --git a/services/thumbnails/pkg/thumbnail/storage/filesystem.go b/services/thumbnails/pkg/thumbnail/storage/filesystem.go
index dd18e88f57..0188fc8b43 100644
--- a/services/thumbnails/pkg/thumbnail/storage/filesystem.go
+++ b/services/thumbnails/pkg/thumbnail/storage/filesystem.go
@@ -31,6 +31,7 @@ type FileSystem struct {
 	logger log.Logger
 }
 
+// Stat returns if a file for the given key exists on the filesystem
 func (s FileSystem) Stat(key string) bool {
 	img := filepath.Join(s.root, filesDir, key)
 	if _, err := os.Stat(img); err != nil {
@@ -39,6 +40,7 @@ func (s FileSystem) Stat(key string) bool {
 	return true
 }
 
+// Get returns the file content for the given key
 func (s FileSystem) Get(key string) ([]byte, error) {
 	img := filepath.Join(s.root, filesDir, key)
 	content, err := os.ReadFile(img)
@@ -51,6 +53,7 @@ func (s FileSystem) Get(key string) ([]byte, error) {
 	return content, nil
 }
 
+// Put stores image data in the file system for the given key
 func (s FileSystem) Put(key string, img []byte) error {
 	imgPath := filepath.Join(s.root, filesDir, key)
 	dir := filepath.Dir(imgPath)
diff --git a/services/thumbnails/pkg/thumbnail/storage/inmemory.go b/services/thumbnails/pkg/thumbnail/storage/inmemory.go
deleted file mode 100644
index 1768318518..0000000000
--- a/services/thumbnails/pkg/thumbnail/storage/inmemory.go
+++ /dev/null
@@ -1,50 +0,0 @@
-package storage
-
-import (
-	"strings"
-)
-
-// NewInMemoryStorage creates a new InMemory instance.
-func NewInMemoryStorage() InMemory {
-	return InMemory{
-		store: make(map[string][]byte),
-	}
-}
-
-// InMemory represents an in memory storage for thumbnails
-// Can be used during development
-type InMemory struct {
-	store map[string][]byte
-}
-
-func (s InMemory) Stat(key string) bool {
-	_, exists := s.store[key]
-	return exists
-}
-
-// Get loads the thumbnail from memory.
-func (s InMemory) Get(key string) ([]byte, error) {
-	return s.store[key], nil
-}
-
-// Set stores the thumbnail in memory.
-func (s InMemory) Put(key string, thumbnail []byte) error {
-	s.store[key] = thumbnail
-	return nil
-}
-
-// BuildKey generates a unique key to store and retrieve the thumbnail.
-func (s InMemory) BuildKey(r Request) string {
-	parts := []string{
-		r.Checksum,
-		r.Resolution.String(),
-	}
-
-	if r.Characteristic != "" {
-		parts = append(parts, r.Characteristic)
-	}
-
-	parts = append(parts, strings.Join(r.Types, ","))
-
-	return strings.Join(parts, "+")
-}
diff --git a/services/thumbnails/pkg/thumbnail/storage/inmemory_test.go b/services/thumbnails/pkg/thumbnail/storage/inmemory_test.go
deleted file mode 100644
index 9f33a6ae49..0000000000
--- a/services/thumbnails/pkg/thumbnail/storage/inmemory_test.go
+++ /dev/null
@@ -1,65 +0,0 @@
-package storage_test
-
-import (
-	"image"
-	"testing"
-
-	tAssert "github.com/stretchr/testify/assert"
-
-	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/thumbnail/storage"
-)
-
-func TestInMemory_BuildKey(t *testing.T) {
-	tests := []struct {
-		r    storage.Request
-		want string
-	}{
-		{
-			r: storage.Request{
-				Checksum: "cs",
-				Types:    []string{"png", "jpg"},
-				Resolution: image.Rectangle{
-					Min: image.Point{
-						X: 1,
-						Y: 2,
-					},
-					Max: image.Point{
-						X: 3,
-						Y: 4,
-					},
-				},
-				Characteristic: "",
-			},
-			want: "cs+(1,2)-(3,4)+png,jpg",
-		},
-		{
-			r: storage.Request{
-				Checksum: "cs",
-				Types:    []string{"png", "jpg"},
-				Resolution: image.Rectangle{
-					Min: image.Point{
-						X: 1,
-						Y: 2,
-					},
-					Max: image.Point{
-						X: 3,
-						Y: 4,
-					},
-				},
-				Characteristic: "fill",
-			},
-			want: "cs+(1,2)-(3,4)+fill+png,jpg",
-		},
-	}
-
-	s := storage.InMemory{}
-	assert := tAssert.New(t)
-
-	for _, tt := range tests {
-		tt := tt
-		t.Run("", func(t *testing.T) {
-			assert.Equal(s.BuildKey(tt.r), tt.want)
-		})
-	}
-
-}
diff --git a/services/thumbnails/pkg/thumbnail/storage/storage.go b/services/thumbnails/pkg/thumbnail/storage/storage.go
index 591b05bdc1..143ab69bc4 100644
--- a/services/thumbnails/pkg/thumbnail/storage/storage.go
+++ b/services/thumbnails/pkg/thumbnail/storage/storage.go
@@ -16,7 +16,7 @@ type Request struct {
 	// The resolution of the thumbnail
 	Resolution image.Rectangle
 	// Characteristic defines the different image characteristics,
-	// for example, if its scaled up to fit in the bounding box or not,
+	// for example, if it's scaled up to fit in the bounding box or not,
 	// is it a chroma version of the image, and so on...
 	// the main propose for this is to be able to differentiate between images which have
 	// the same resolution but different characteristics.
@@ -25,8 +25,8 @@ type Request struct {
 
 // Storage defines the interface for a thumbnail store.
 type Storage interface {
-	Stat(string) bool
-	Get(string) ([]byte, error)
-	Put(string, []byte) error
-	BuildKey(Request) string
+	Stat(key string) bool
+	Get(key string) ([]byte, error)
+	Put(key string, img []byte) error
+	BuildKey(r Request) string
 }
diff --git a/services/thumbnails/pkg/thumbnail/thumbnail.go b/services/thumbnails/pkg/thumbnail/thumbnail.go
index 2871f1b8fc..48ffab36bd 100644
--- a/services/thumbnails/pkg/thumbnail/thumbnail.go
+++ b/services/thumbnails/pkg/thumbnail/thumbnail.go
@@ -7,11 +7,12 @@ import (
 	"mime"
 
 	"github.com/owncloud/ocis/v2/ocis-pkg/log"
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/thumbnail/storage"
 )
 
 var (
-	// SupportedMimeTypes contains a all mimetypes which are supported by the thumbnailer.
+	// SupportedMimeTypes contains an all mimetypes which are supported by the thumbnailer.
 	SupportedMimeTypes = map[string]struct{}{
 		"image/png":                       {},
 		"image/jpg":                       {},
@@ -28,7 +29,7 @@ var (
 	}
 )
 
-// Request bundles information needed to generate a thumbnail for afile
+// Request bundles information needed to generate a thumbnail for a file
 type Request struct {
 	Resolution image.Rectangle
 	Encoder    Encoder
@@ -41,37 +42,48 @@ type Request struct {
 type Manager interface {
 	// Generate creates a thumbnail and stores it.
 	// The function returns a key with which the actual file can be retrieved.
-	Generate(Request, interface{}) (string, error)
+	Generate(r Request, img interface{}) (string, error)
 	// CheckThumbnail checks if a thumbnail with the requested attributes exists.
 	// The function will return a status if the file exists and the key to the file.
-	CheckThumbnail(Request) (string, bool)
+	CheckThumbnail(r Request) (string, bool)
 	// GetThumbnail will load the thumbnail from the storage and return its content.
 	GetThumbnail(key string) ([]byte, error)
 }
 
 // NewSimpleManager creates a new instance of SimpleManager
-func NewSimpleManager(resolutions Resolutions, storage storage.Storage, logger log.Logger) SimpleManager {
+func NewSimpleManager(resolutions Resolutions, storage storage.Storage, logger log.Logger, maxInputWidth, maxInputHeight int) SimpleManager {
 	return SimpleManager{
-		storage:     storage,
-		logger:      logger,
-		resolutions: resolutions,
+		storage:      storage,
+		logger:       logger,
+		resolutions:  resolutions,
+		maxDimension: image.Point{X: maxInputWidth, Y: maxInputHeight},
 	}
 }
 
 // SimpleManager is a simple implementation of Manager
 type SimpleManager struct {
-	storage     storage.Storage
-	logger      log.Logger
-	resolutions Resolutions
+	storage      storage.Storage
+	logger       log.Logger
+	resolutions  Resolutions
+	maxDimension image.Point
 }
 
+// Generate creates a thumbnail and stores it
 func (s SimpleManager) Generate(r Request, img interface{}) (string, error) {
 	var match image.Rectangle
+	var inputDimensions image.Rectangle
 	switch m := img.(type) {
 	case *gif.GIF:
 		match = s.resolutions.ClosestMatch(r.Resolution, m.Image[0].Bounds())
+		inputDimensions = m.Image[0].Bounds()
 	case image.Image:
 		match = s.resolutions.ClosestMatch(r.Resolution, m.Bounds())
+		inputDimensions = m.Bounds()
+	}
+
+	// validate max input image dimensions - 6016x4000
+	if inputDimensions.Size().X > s.maxDimension.X || inputDimensions.Size().Y > s.maxDimension.Y {
+		return "", errors.ErrImageTooLarge
 	}
 
 	thumbnail, err := r.Generator.Generate(match, img, r.Processor)
@@ -92,11 +104,13 @@ func (s SimpleManager) Generate(r Request, img interface{}) (string, error) {
 	return k, nil
 }
 
+// CheckThumbnail checks if a thumbnail with the requested attributes exists.
 func (s SimpleManager) CheckThumbnail(r Request) (string, bool) {
 	k := s.storage.BuildKey(mapToStorageRequest(r))
 	return k, s.storage.Stat(k)
 }
 
+// GetThumbnail will load the thumbnail from the storage and return its content.
 func (s SimpleManager) GetThumbnail(key string) ([]byte, error) {
 	return s.storage.Get(key)
 }
diff --git a/services/thumbnails/pkg/thumbnail/thumbnail_test.go b/services/thumbnails/pkg/thumbnail/thumbnail_test.go
index fc4c979642..2a046e15f5 100644
--- a/services/thumbnails/pkg/thumbnail/thumbnail_test.go
+++ b/services/thumbnails/pkg/thumbnail/thumbnail_test.go
@@ -1,8 +1,12 @@
 package thumbnail
 
 import (
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/errors"
+	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/preprocessor"
+	"github.com/stretchr/testify/assert"
 	"image"
 	"os"
+	"path"
 	"path/filepath"
 	"testing"
 
@@ -17,11 +21,11 @@ type NoOpManager struct {
 	storage.Storage
 }
 
-func (m NoOpManager) BuildKey(r storage.Request) string {
+func (m NoOpManager) BuildKey(_ storage.Request) string {
 	return ""
 }
 
-func (m NoOpManager) Set(username, key string, thumbnail []byte) error {
+func (m NoOpManager) Set(_, _ string, _ []byte) error {
 	return nil
 }
 
@@ -31,6 +35,8 @@ func BenchmarkGet(b *testing.B) {
 		Resolutions{},
 		NoOpManager{},
 		log.NewLogger(),
+		6016,
+		4000,
 	)
 
 	res, _ := ParseResolution("32x32")
@@ -126,10 +132,59 @@ func TestPrepareRequest(t *testing.T) {
 				return
 			}
 
-			// func's are not reflactable, ignore
+			// funcs are not reflactable, ignore
 			if diff := cmp.Diff(tt.want, got, cmpopts.IgnoreFields(Request{}, "Processor")); diff != "" {
 				t.Errorf("PrepareRequest(): %v", diff)
 			}
 		})
 	}
 }
+
+func TestPreviewGenerationTooBigImage(t *testing.T) {
+	tests := []struct {
+		name     string
+		fileName string
+		mimeType string
+	}{
+		{name: "png", mimeType: "image/png", fileName: "../../testdata/oc.png"},
+		{name: "gif", mimeType: "image/gif", fileName: "../../testdata/oc.gif"},
+		{name: "ggs", mimeType: "application/vnd.geogebra.slides", fileName: "../../testdata/test.ggs"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sut := NewSimpleManager(
+				Resolutions{},
+				NoOpManager{},
+				log.NewLogger(),
+				1024,
+				768,
+			)
+
+			res, _ := ParseResolution("32x32")
+			req := Request{
+				Resolution: res,
+				Checksum:   "1872ade88f3013edeb33decd74a4f947",
+			}
+			cwd, _ := os.Getwd()
+			p := filepath.Join(cwd, tt.fileName)
+			f, _ := os.Open(p)
+			defer f.Close()
+
+			preproc := preprocessor.ForType(tt.mimeType, nil)
+			convert, err := preproc.Convert(f)
+			if err != nil {
+				return
+			}
+
+			ext := path.Ext(tt.fileName)
+			req.Encoder, _ = EncoderForType(ext)
+			generate, err := sut.Generate(req, convert)
+			if err != nil {
+				return
+			}
+			assert.ErrorIs(t, err, errors.ErrImageTooLarge)
+			assert.Equal(t, "", generate)
+		})
+	}
+}
diff --git a/services/thumbnails/testdata/oc.gif b/services/thumbnails/testdata/oc.gif
new file mode 100644
index 0000000000..e4f4e9e28b
Binary files /dev/null and b/services/thumbnails/testdata/oc.gif differ
diff --git a/services/thumbnails/testdata/test.ggs b/services/thumbnails/testdata/test.ggs
new file mode 100644
index 0000000000..078ba5c4da
Binary files /dev/null and b/services/thumbnails/testdata/test.ggs differ