Vulnerability · Published Sep 9, 2026 · Assigned by GitHub_M
CVE-2026-87015Open WebUI: A user's session cookies are sent to tool servers configured for bearer authentication
Medium 6.8
In plain English
A medium-severity security flaw in open-webui from open-webui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.6.27 until 0.11.1, backend/open_webui/utils/tools.py captured a cookie jar from the enclosing connection loop instead of binding it to each external tool callable. When multiple tool servers were attached and a session or system OAuth connection was processed last, a request to a different server configured for bearer authentication could include the calling user's Open WebUI session cookies, allowing that server's operator to reuse the session and take over the account. This issue is fixed in version 0.11.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | open-webui | 0.11.1 | GHSA-p78m-89r6-pgf7 |
| PyPI | open-webui | 0.11.1 | PYSEC-2026-4124 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| open-webui | open-webui | >= 0.6.27, < 0.11.1 |
Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- https://github.com/open-webui/open-webui/security/advisories/GHSA-p78m-89r6-pgf7 x_refsource_CONFIRM
- https://github.com/open-webui/open-webui/pull/28630 x_refsource_MISC
- https://github.com/open-webui/open-webui/commit/cd9db21c5276807a2975ddba17cef369ad1114b7 x_refsource_MISC
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1 x_refsource_MISC