CVE-2026-87015

MEDIUM CVSS 3.1: 6.8 EPSS 0.28%
Updated Sep 10, 2026
Open
Parameter Value
CVSS 6.8 (MEDIUM)
Fixed In 0.11.1
Type CWE-201
Vendor Open
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption

CVSS Vector v3.1

Weakness Type (CWE)