CVEvulnerability

CVE-2026-87011

7.5 HIGH Published 2026-09-09 Modified 2026-09-15 Official page ↗
Status
Analyzed
Published
2026-09-09
Last modified
2026-09-15
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-405, CWE-770

Description

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.

Affected configurations

• openwebui open webui (>= 0.9.0 < 0.11.1)

Related

Weakness · CWE (2)

  • CWE-405 Asymmetric Resource Consumption (Amplification) weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References