CVE-2026-87011
Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout
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.
INFO
Published Date :
Sept. 9, 2026, 9:17 p.m.
Last Modified :
Sept. 15, 2026, 4:26 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Open WebUI to version 0.11.1.
- Ensure ENABLE_OAUTH_BACKCHANNEL_LOGOUT is configured securely.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-87011.
| URL | 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-87011 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-87011
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-87011 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-87011 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 15, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* versions from (including) 0.9.0 up to (excluding) 0.11.1 Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c Types: Patch Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/releases/tag/v0.11.1 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 14, 2026
Action Type Old Value New Value Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w Added SSVC {'id': 'CVE-2026-87011', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-14T13:41:36.439676Z'} -
New CVE Received by [email protected]
Sep. 09, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-405 Added CWE CWE-770 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/87xxx/CVE-2026-87011.json">CVE-2026-87011</a> Added Reference https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c Added Reference https://github.com/open-webui/open-webui/releases/tag/v0.11.1 Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w