A vulnerability in the @payloadcms/storage-vercel-blob package allows authenticated users to bypass access control for client uploads in certain versions. This occurs because client upload access does not consistently enforce the collection-level access permissions. The issue affects versions >=3.25.0 <3.90.0 and >=4.0.0-canary.0 <4.0.0-canary.34. A fix is available in versions 3.90.0 and 4.0.0-canary.34, which require authentication and proper collection-level access for uploads.