CVE-2026-87015: open-webui

Vulnerability summary

CVE-2026-87015 is a medium (CVSS 6.8) vulnerability in open-webui. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 09-09-2026
   PublishedVulnerability first disclosed.
2. 10-09-2026
   Last modifiedVulnerability information updated.

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.

• CWE-201Insertion of Sensitive Information Into Sent DataThe code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.