high7.5
CVE-2026-87011
Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | open-webui | >= 0.9.0, <= 0.11.0 | 0.11.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Openwebui | Open Webui | from 0.9.0 before 0.11.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3g9q-v48f-hh9w
- https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w
- https://nvd.nist.gov/vuln/detail/CVE-2026-87011
- https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1