CVE-2026-42276 MEDIUM

CVE-2026-42276: Onyx: IDOR in /chat/stop-chat-session allows any authenticated user to interrupt other users chat sessions

Vendor Onyx-Dot-App
Product onyx
Weakness CWE-639 · IDOR
Published May 8, 2026
Last update May 8, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

Onyx is an open-source AI platform. Prior to versions 3.0.9, 3.1.6, and 3.2.6, the POST /chat/stop-chat-session/{chat_session_id} endpoint lets any authenticated user stop any other user's active chat session. The endpoint checks authentication but never verifies the session belongs to the caller. An attacker who knows a chat session UUID can kill another user's LLM generation mid-stream. This issue has been patched in versions 3.0.9, 3.1.6, and 3.2.6.

Key dates

02Disclosure timeline

May 8, 2026 CVE published
May 8, 2026 Record updated

Related vulnerabilities

04Related CVE