diff --git a/changelog/unreleased/avoid-panic-in-cache.md b/changelog/unreleased/avoid-panic-in-cache.md
new file mode 100644
index 0000000000..9b2d0d9650
--- /dev/null
+++ b/changelog/unreleased/avoid-panic-in-cache.md
@@ -0,0 +1,5 @@
+Bugfix: fixed panic in receivedsharecache pkg
+
+The receivedsharecache pkg would sometime run into concurrent map writes. This is fixed by using maptimesyncedcache pkg instead of a plain map.
+
+https://github.com/cs3org/reva/pull/4424
diff --git a/pkg/share/manager/jsoncs3/receivedsharecache/receivedsharecache.go b/pkg/share/manager/jsoncs3/receivedsharecache/receivedsharecache.go
index 65111e7e7c..1080a808d1 100644
--- a/pkg/share/manager/jsoncs3/receivedsharecache/receivedsharecache.go
+++ b/pkg/share/manager/jsoncs3/receivedsharecache/receivedsharecache.go
@@ -32,6 +32,7 @@ import (
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/v2/pkg/appctx"
 	"github.com/cs3org/reva/v2/pkg/errtypes"
+	"github.com/cs3org/reva/v2/pkg/storage/utils/decomposedfs/mtimesyncedcache"
 	"github.com/cs3org/reva/v2/pkg/storage/utils/metadata"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
@@ -46,7 +47,7 @@ const tracerName = "receivedsharecache"
 type Cache struct {
 	lockMap sync.Map
 
-	ReceivedSpaces map[string]*Spaces
+	ReceivedSpaces mtimesyncedcache.Map[string, *Spaces]
 
 	storage metadata.Storage
 	ttl     time.Duration
@@ -74,7 +75,7 @@ type State struct {
 // New returns a new Cache instance
 func New(s metadata.Storage, ttl time.Duration) Cache {
 	return Cache{
-		ReceivedSpaces: map[string]*Spaces{},
+		ReceivedSpaces: mtimesyncedcache.Map[string, *Spaces]{},
 		storage:        s,
 		ttl:            ttl,
 		lockMap:        sync.Map{},
@@ -97,7 +98,7 @@ func (c *Cache) Add(ctx context.Context, userID, spaceID string, rs *collaborati
 	span.SetAttributes(attribute.String("cs3.userid", userID))
 	defer unlock()
 
-	if c.ReceivedSpaces[userID] == nil {
+	if _, ok := c.ReceivedSpaces.Load(userID); !ok {
 		err := c.syncWithLock(ctx, userID)
 		if err != nil {
 			return err
@@ -111,7 +112,8 @@ func (c *Cache) Add(ctx context.Context, userID, spaceID string, rs *collaborati
 	persistFunc := func() error {
 		c.initializeIfNeeded(userID, spaceID)
 
-		receivedSpace := c.ReceivedSpaces[userID].Spaces[spaceID]
+		rss, _ := c.ReceivedSpaces.Load(userID)
+		receivedSpace := rss.Spaces[spaceID]
 		if receivedSpace.States == nil {
 			receivedSpace.States = map[string]*State{}
 		}
@@ -171,10 +173,11 @@ func (c *Cache) Get(ctx context.Context, userID, spaceID, shareID string) (*Stat
 	if err != nil {
 		return nil, err
 	}
-	if c.ReceivedSpaces[userID] == nil || c.ReceivedSpaces[userID].Spaces[spaceID] == nil {
+	rss, ok := c.ReceivedSpaces.Load(userID)
+	if !ok || rss.Spaces[spaceID] == nil {
 		return nil, nil
 	}
-	return c.ReceivedSpaces[userID].Spaces[spaceID].States[shareID], nil
+	return rss.Spaces[spaceID].States[shareID], nil
 }
 
 // List returns a list of received shares for a given user
@@ -192,7 +195,8 @@ func (c *Cache) List(ctx context.Context, userID string) (map[string]*Space, err
 	}
 
 	spaces := map[string]*Space{}
-	for spaceID, space := range c.ReceivedSpaces[userID].Spaces {
+	rss, _ := c.ReceivedSpaces.Load(userID)
+	for spaceID, space := range rss.Spaces {
 		spaceCopy := &Space{
 			States: map[string]*State{},
 		}
@@ -220,9 +224,10 @@ func (c *Cache) syncWithLock(ctx context.Context, userID string) error {
 	jsonPath := userJSONPath(userID)
 	span.AddEvent("updating cache")
 	//  - update cached list of created shares for the user in memory if changed
+	rss, _ := c.ReceivedSpaces.Load(userID)
 	dlres, err := c.storage.Download(ctx, metadata.DownloadRequest{
 		Path:        jsonPath,
-		IfNoneMatch: []string{c.ReceivedSpaces[userID].etag},
+		IfNoneMatch: []string{rss.etag},
 	})
 	switch err.(type) {
 	case nil:
@@ -248,7 +253,7 @@ func (c *Cache) syncWithLock(ctx context.Context, userID string) error {
 	}
 	newSpaces.etag = dlres.Etag
 
-	c.ReceivedSpaces[userID] = newSpaces
+	c.ReceivedSpaces.Store(userID, newSpaces)
 	span.SetStatus(codes.Ok, "")
 	return nil
 }
@@ -259,12 +264,13 @@ func (c *Cache) persist(ctx context.Context, userID string) error {
 	defer span.End()
 	span.SetAttributes(attribute.String("cs3.userid", userID))
 
-	if c.ReceivedSpaces[userID] == nil {
+	rss, ok := c.ReceivedSpaces.Load(userID)
+	if !ok {
 		span.SetStatus(codes.Ok, "no received shares")
 		return nil
 	}
 
-	createdBytes, err := json.Marshal(c.ReceivedSpaces[userID])
+	createdBytes, err := json.Marshal(rss)
 	if err != nil {
 		span.RecordError(err)
 		span.SetStatus(codes.Error, err.Error())
@@ -280,11 +286,11 @@ func (c *Cache) persist(ctx context.Context, userID string) error {
 	ur := metadata.UploadRequest{
 		Path:        jsonPath,
 		Content:     createdBytes,
-		IfMatchEtag: c.ReceivedSpaces[userID].etag,
+		IfMatchEtag: rss.etag,
 	}
 	// when there is no etag in memory make sure the file has not been created on the server, see https://www.rfc-editor.org/rfc/rfc9110#field.if-match
 	// > If the field value is "*", the condition is false if the origin server has a current representation for the target resource.
-	if c.ReceivedSpaces[userID].etag == "" {
+	if rss.etag == "" {
 		ur.IfNoneMatch = []string{"*"}
 	}
 
@@ -303,12 +309,9 @@ func userJSONPath(userID string) string {
 }
 
 func (c *Cache) initializeIfNeeded(userID, spaceID string) {
-	if c.ReceivedSpaces[userID] == nil {
-		c.ReceivedSpaces[userID] = &Spaces{
-			Spaces: map[string]*Space{},
-		}
-	}
-	if spaceID != "" && c.ReceivedSpaces[userID].Spaces[spaceID] == nil {
-		c.ReceivedSpaces[userID].Spaces[spaceID] = &Space{}
+	rss, _ := c.ReceivedSpaces.LoadOrStore(userID, &Spaces{Spaces: map[string]*Space{}})
+	if spaceID != "" && rss.Spaces[spaceID] == nil {
+		rss.Spaces[spaceID] = &Space{}
+		c.ReceivedSpaces.Store(userID, rss)
 	}
 }