CVE Catalog

CVE-2026-87015

MediumCVSS 6.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.28%

20th percentile - higher than 20% of all known CVEs

Summary

Open WebUI from 0.6.27 to 0.11.1 incorrectly captures a cookie jar in external tools, potentially leaking user session cookies to the operator of another tool server. When multiple tool servers are attached and a session or OAuth connection is processed last, requests to a different server may include the user's Open WebUI session cookies, allowing account takeover. Fixed in 0.11.1.

Risk Assessment

A malicious tool server operator can hijack a user's session and gain full account access, posing a serious security breach.

Recommendation

Immediately upgrade to version 0.11.1 or later and limit trust in external tool servers.

Other vulnerabilities in Open WebUI

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS