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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c	Patch
https://github.com/open-webui/open-webui/releases/tag/v0.11.1	Release Notes
https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w	Exploit Vendor Advisory
https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-09-09 21:17

Updated : 2026-09-15 16:26

NVD link : CVE-2026-87011

Mitre link : CVE-2026-87011

CVE.ORG link : CVE-2026-87011

JSON object : View

Products Affected

openwebui

open_webui

CWE

CWE-405

Asymmetric Resource Consumption (Amplification)

CWE-770

Allocation of Resources Without Limits or Throttling

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