CVE-2026-87011— Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout
Quick assessment
Affected
open-webui open-webui
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Open WebUI 是一个可扩展、功能丰富且用户友好的自托管 AI 平台。 在 0.9.0 至 0.11.1 版本中，未认证的 处理器（位于 中）在验证提交的登出令牌之前，会先获取 OIDC 发现文档和签名密钥。由于每次请求都会重复进行未缓存的网络获取，且签名密钥查找操作会阻塞异步事件循环，因此当 启用时，携带无效令牌的请求可能会导致单工作进程实例阻塞，并向身份提供者（Identity Provider）放大流量。 该问题已在 0.11.1 版本中修复。
Possible ATT&CK Techniques 1 AI
T1059 · Command and Scripting Interpreter
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I. Basic Information for CVE-2026-87011
Vulnerability Information
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Vulnerability Title
Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
不对称的资源消耗(放大攻击)
Source: CVE Program / CVE List V5
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| open-webui | open-webui | >= 0.9.0, < 0.11.1 | - |
|
II. Public POCs for CVE-2026-87011
| # | POC Description | Source Link | Shenlong Link |
|---|
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Other References for CVE-2026-87011 (2)
Same Patch Batch · open-webui · 2026-09-09 · 16 CVEs total
| CVE-2026-87995 | 8.7 HIGH | Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcodin |
| CVE-2026-87016 | 8.1 HIGH | Open WebUI: Sign-in as another user via wildcard characters in the OAuth subject claim on |
| CVE-2026-87996 | 7.7 HIGH | Open WebUI: SSRF into internal services via DNS rebinding in the Playwright web loader |
| CVE-2026-87998 | 7.1 HIGH | Open WebUI: Non-admin users can delete admin-owned external knowledge connections via know |
| CVE-2026-87999 | 7.1 HIGH | Open WebUI: Any authenticated user can reach the Azure platform channel via server-side we |
| CVE-2026-87015 | 6.8 MEDIUM | Open WebUI: A user's session cookies are sent to tool servers configured for bearer authen |
| CVE-2026-87014 | 6.5 MEDIUM | Open WebUI: Admin demoted through SSO role sync keeps read and write access to all users' |
| CVE-2026-88000 | 6.5 MEDIUM | Open WebUI: Any authenticated user can hang the server via message deletion in a cyclic ch |
| CVE-2026-88002 | 6.5 MEDIUM | Open WebUI: Any authenticated user can hang the server via a cyclic chat message history |
| CVE-2026-88001 | 5.0 MEDIUM | Open WebUI: Server-side fetches reach blocked and internal hosts via unvalidated HTTP redi |
| CVE-2026-87012 | 4.3 MEDIUM | Open WebUI: Any authenticated user can suppress calendar alerts instance-wide via a non-nu |
| CVE-2026-87013 | 4.3 MEDIUM | Open WebUI: Any authenticated user can start a non-terminating request via a folder parent |
| CVE-2026-87017 | 4.3 MEDIUM | Open WebUI: Inaccessible knowledge bases are exposed through the built-in knowledge tool o |
| CVE-2026-87994 | 4.3 MEDIUM | Open WebUI: Channel members can overwrite another member's message via the chat completion |
| CVE-2026-87997 | 4.3 MEDIUM | Open WebUI: Any authenticated user can inject chats into another user's folder via chat co |
IV. Related Vulnerabilities
Same product: open-webui
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CVE-2026-88002
Open WebUI: Any authenticated user can hang the server via a -
CVE-2026-88001
Open WebUI: Server-side fetches reach blocked and internal h -
CVE-2026-88000
Open WebUI: Any authenticated user can hang the server via m -
CVE-2026-87999
Open WebUI: Any authenticated user can reach the Azure platf -
CVE-2026-87998
Open WebUI: Non-admin users can delete admin-owned external
Same vendor: open-webui
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Open WebUI: Any authenticated user can hang the server via a -
CVE-2026-88001
Open WebUI: Server-side fetches reach blocked and internal h -
CVE-2026-88000
Open WebUI: Any authenticated user can hang the server via m -
CVE-2026-87999
Open WebUI: Any authenticated user can reach the Azure platf -
CVE-2026-87998
Open WebUI: Non-admin users can delete admin-owned external
Same weakness: CWE-405
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V. Comments for CVE-2026-87011
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