CVE-2026-87014

Open WebUI, a widely used self-hosted AI interface, fails to invalidate a cached user record when an administrator's role is changed, so authorization decisions for already-established Socket.IO connections keep using the old 'admin' role (CWE-613/CWE-863). The flaw is triggered when an admin is demoted via a trusted role header or an OAuth role mapping in the affected versions: their open Socket.IO connection stays authorized until it closes. A demoted administrator can therefore continue to read and edit every user's collaborative notes after losing their privileges, but the issue requires high privileges up front and grants no new access beyond the notes channel. Versions 0.9.0 through before 0.11.1 are affected, and the fix shipped in 0.11.1. Exploitation probability is currently very low (EPSS 0.3%, not in CISA KEV), with only the upstream GitHub security advisory made public and no known attacks in the wild.

What to do: Upgrade Open WebUI to 0.11.1 or later, where role synchronization invalidates the cached user record. If you cannot patch immediately, terminate active Socket.IO connections (or force logout/re-login) for any user whose role has just been changed, and restrict trusted role headers and OAuth role-mapping claims to genuinely trusted identity providers. After patching, audit collaborative-notes edit history for changes attributable to recently demoted administrators.