CVE-2026-42276 Details
Description
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.
A vulnerability in Onyx, an open-source AI platform, allows authenticated users to disrupt active chat sessions of other users. This issue is present in versions prior to 3.0.9, between 3.1.0 and 3.1.6, and between 3.2.0 and 3.2.6. The vulnerability arises because the POST /chat/stop-chat-session/{chat_session_id} endpoint, while checking authentication, fails to verify if the session belongs to the user making the request. As a result, an attacker with knowledge of a chat session UUID can terminate another user's LLM generation in progress.
Users can update to Onyx versions 3.0.9, 3.1.6, or 3.2.6, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 8, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w | CISA-ADP | ExploitVendor Advisory |
| https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-639 | Authorization Bypass Through User-Controlled Key | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| onyx onyx | < 3.0.9 >= 3.1.0, < 3.1.6 >= 3.2.0, < 3.2.6 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 12, 2026 | Initial Analysis | [email protected] |
| May 8, 2026 | CVE Modified | CISA-ADP |
| May 8, 2026 | New CVE Received | [email protected] |