CVE Catalog

CVE-2026-87011

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

27th percentile - higher than 27% of all known CVEs

Summary

In Open WebUI from 0.9.0 to 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler fetches the OIDC discovery document and signing keys before validating the logout token, causing repeated network fetches and blocking the event loop, enabling a DoS attack on a single-worker instance.

Risk Assessment

An attacker can send invalid tokens, causing server overload and performance degradation of the AI platform.

Recommendation

Update Open WebUI to version 0.11.1 or later to fix the issue.

Other vulnerabilities in Open WebUI

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS