CVE-2026-45402 Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, multiple endpoints accept a user-supplied fileid and attach the referenced file to a resource the caller controls folder knowledge, knowledge-base contents without verifying that the...

CVE-2026-45402 Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, multiple endpoints accept a user-supplied fileid and attach the referenced file to a resource the caller controls folder knowledge, knowledge-base contents without verifying that the...

CVE-2026-45402

Open WebUI CVE-2026-45402 describes a cross-user file access/overwrite vulnerability in offline Open WebUI prior to 0.9.5. Two concrete paths allow attaching a victim’s file_id without verifying ownership: (1) folder knowledge ingestion via POST /api/v1/folders/{id}/update and (2) knowledge-base ...

GHSA-R472-MW7M-967F Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints

Cross-User File Access via Unchecked fileid in Folder Knowledge and Knowledge-Base Attach Endpoints Summary Multiple endpoints accept a user-supplied fileid and attach the referenced file to a resource the caller controls folder knowledge, knowledge-base contents without verifying that the caller...