SB2026051164 - Multiple vulnerabilities in Open WebUI

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper Authorization (CVE-ID: CVE-2026-45365)

CWE-ID: CWE-285 - Improper Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to bypass model access control and invoke restricted models.

The vulnerability exists due to improper authorization in the /openai/chat/completions and /ollama/api/chat HTTP endpoints when handling requests with the exposed bypass_filter query parameter. A remote user can append ?bypass_filter=true to a request URL to bypass model access control and invoke restricted models.

The issue affects the FastAPI route handlers generate_chat_completion in routers/openai.py and routers/ollama.py, where an internal-only parameter is bound from the query string.

2) Improper access control (CVE-ID: CVE-2026-54022)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to improper access control in the ydoc:document:join Socket.IO handler and YdocManager document ID normalization when joining a document room with a crafted document identifier. A remote user can use a note_ document ID instead of note: for a target note to disclose sensitive information.

Exploitation requires authentication and knowledge of or the ability to enumerate the target note ID.

Remediation

Install update from vendor's website.

References

• https://github.com/open-webui/open-webui/security/advisories/GHSA-v6qf-75pr-p96m
• https://github.com/open-webui/open-webui/commit/c0385f60ba049da48d2d5452068586d375303c37
• https://github.com/open-webui/open-webui/security/advisories/GHSA-8788-j68r-3cgh