File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, a low-privileged authenticated user of filebrowser (with create + delete permissions in their own isolated scope) can silently destroy share-link records belonging to any other user — including the administrator — by performing a legitimate DELETE on a file in their own directory whose logical path happens to be a byte-prefix of another user's stored share.Link.Path. The file contents of the victim are not exposed, but the victim's share links are irrevocably wiped. This vulnerability is fixed in 2.63.6.

Affected: Go: github.com/filebrowser/filebrowser, Go: github.com/filebrowser/filebrowser/v2

### Summary A low-privileged authenticated user of filebrowser (with `create` + `delete` permissions in their own isolated scope) can silently destroy share-link records belonging to any other user — including the administrator — by performing a legitimate DELETE on a file in their own directory whose logical path happens to be a byte-prefix of another user's stored `share.Link.Path`. The file contents of the victim are not exposed, but the victim's share links are irrevocably wiped.

### Details `resourceDeleteHandler` in `http/resource.go` cleans up any share records that reference a deleted file by calling:

```go // http/resource.go err = d.store.Share.DeleteWithPathPrefix(file.Path) ```

`file.Path` here is the *logical* path from the URL of the deleting user's request (e.g. `/a`), not the absolute filesystem path. It is passed as-is to the bolt backend:

```go // storage/bolt/share.go func (s shareBackend) DeleteWithPathPrefix(pathPrefix string) error { var links []share.Link if err := s.db.Prefix("Path", pathPrefix, &links); err != nil { return err } for _, link := range links { err = errors.Join(err, s.db.DeleteStruct(&share.Link{Hash: link.Hash})) } return err } ``` **Why the design contradicts this behavior.** `share.Link` carries a `UserID` field and the application elsewhere treats shares as per-user owned resources. `shareDeleteHandler` explicitly enforces `link.UserID != d.user.ID && !d.user.Perm.Admin → 403`. The file-de…