CVE-2026-87015

MEDIUM 6.8

Open WebUI: A user's session cookies are sent to tool servers configured for bearer authentication

CVSS Score

6.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-201
Vendor	open-webui
Product	open-webui
Published	Sep 9, 2026
Last Updated	Sep 10, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

open-webui / open-webui

>= 0.6.27, < 0.11.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/open-webui/open-webui/security/advisories/GHSA-p78m-89r6-pgf7 github.com: https://github.com/open-webui/open-webui/pull/28630 github.com: https://github.com/open-webui/open-webui/commit/cd9db21c5276807a2975ddba17cef369ad1114b7 github.com: https://github.com/open-webui/open-webui/releases/tag/v0.11.1