CVE-2026-87011
highOpen WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.
Vendor / product: Openwebui — open webui
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c security-advisories@github.com
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1 security-advisories@github.com
- https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w security-advisories@github.com
- https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w 134c704f-9b21-4f2e-91b3-4a467353bcc0