Insertion of Sensitive Information Into Sent Data in Open WebUI - CVE-2026-87015
Published: September 28, 2026
Vulnerability identifier: #VU152701
CSH Severity: Medium
CVSS v4: 7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-87015
CWE-ID: CWE-201
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to obtain user session credentials.
The vulnerability exists due to improper handling of connection-specific cookie jars in the tool loading routine in backend/open_webui/utils/tools.py when processing a tool call with multiple external tool servers. A remote attacker can operate a bearer-authenticated tool server configured by an administrator to obtain user session credentials.
A user must trigger a tool call. Exploitation requires at least two attached tool servers, including a session or system OAuth connection that is processed last.
Affected software
Open WebUI
How to mitigate CVE-2026-87015
Install security update from vendor's website.
Open WebUI - update to 0.11.1