CVE-2026-87011

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler in backend/open_webui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout token. Each request repeated uncached network fetches, and the signing-key lookup blocked the async event loop, so requests carrying invalid tokens could stall the single-worker instance and amplify traffic to the identity provider when ENABLE_OAUTH_BACKCHANNEL_LOGOUT was enabled. This issue is fixed in version 0.11.1.

• CWE-405
• CWE-770

• https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142cPatch
• https://github.com/open-webui/open-webui/releases/tag/v0.11.1Release Notes
• https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9wExploit, Vendor Advisory
• https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9wExploit, Vendor Advisory

Published

Sep 9, 2026

Last Modified

Sep 15, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-86993n8n is an open source workflow automation platform. Prior to…4.9
• CVE-2026-86994n8n is an open source workflow automation platform. Prior to…4.3
• CVE-2026-86995n8n is an open source workflow automation platform. Prior to…4.3
• CVE-2026-86996n8n is an open source workflow automation platform. Prior to…5.4
• CVE-2026-8700Crypt::DSA versions before 1.20 for Perl generate seeds usin…7.3
• CVE-2026-8701The GNTT Post Title Ticker plugin for WordPress is vulnerabl…6.4
• CVE-2026-87012Open WebUI is an extensible, feature-rich, and user-friendly…4.3
• CVE-2026-87013Open WebUI is an extensible, feature-rich, and user-friendly…4.3
• CVE-2026-87014Open WebUI is an extensible, feature-rich, and user-friendly…6.5
• CVE-2026-87015Open WebUI is an extensible, feature-rich, and user-friendly…6.8
• CVE-2026-87016Open WebUI is an extensible, feature-rich, and user-friendly…8.1
• CVE-2026-87017Open WebUI is an extensible, feature-rich, and user-friendly…4.3