1 files changed, 12 insertions, 4 deletions
diff --git a/Jellyfin.Api/Controllers/LibraryStructureController.cs b/Jellyfin.Api/Controllers/LibraryStructureController.cs
index e46795554b..5c596c21b9 100644
--- a/Jellyfin.Api/Controllers/LibraryStructureController.cs
+++ b/Jellyfin.Api/Controllers/LibraryStructureController.cs
@@ -14,6 +14,7 @@ using MediaBrowser.Common.Api;
 using MediaBrowser.Controller;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Configuration;
 using MediaBrowser.Model.Entities;
@@ -122,12 +123,14 @@ public class LibraryStructureController : BaseJellyfinApiController
     /// <param name="newName">The new name.</param>
     /// <param name="refreshLibrary">Whether to refresh the library.</param>
     /// <response code="204">Folder renamed.</response>
+    /// <response code="400">The new name is not a valid library name.</response>
     /// <response code="404">Library doesn't exist.</response>
     /// <response code="409">Library already exists.</response>
-    /// <returns>A <see cref="NoContentResult"/> on success, a <see cref="NotFoundResult"/> if the library doesn't exist, a <see cref="ConflictResult"/> if the new name is already taken.</returns>
+    /// <returns>A <see cref="NoContentResult"/> on success, a <see cref="BadRequestResult"/> if the new name is invalid, a <see cref="NotFoundResult"/> if the library doesn't exist, a <see cref="ConflictResult"/> if the new name is already taken.</returns>
     /// <exception cref="ArgumentNullException">The new name may not be null.</exception>
     [HttpPost("Name")]
     [ProducesResponseType(StatusCodes.Status204NoContent)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
     [ProducesResponseType(StatusCodes.Status404NotFound)]
     [ProducesResponseType(StatusCodes.Status409Conflict)]
     public ActionResult RenameVirtualFolder(
@@ -147,10 +150,15 @@ public class LibraryStructureController : BaseJellyfinApiController
 
         var rootFolderPath = _appPaths.DefaultUserViewsPath;
 
-        var currentPath = Path.Combine(rootFolderPath, name);
-        var newPath = Path.Combine(rootFolderPath, newName);
+        // Both names are caller supplied, so they have to be confined to the libraries root.
+        var newPath = FileSystemHelper.GetChildPath(rootFolderPath, newName);
+        if (newPath is null)
+        {
+            return BadRequest("The new name is not a valid library name.");
+        }
 
-        if (!Directory.Exists(currentPath))
+        var currentPath = FileSystemHelper.GetChildPath(rootFolderPath, name);
+        if (currentPath is null || !Directory.Exists(currentPath))
         {
             return NotFound("The media collection does not exist.");
         }