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MEDIUM · 4.3

CVE-2026-42276

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...

Vulnerability 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.

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW

Affected Products

VendorProductVersions
OnyxOnyx< 3.0.9

Related Weaknesses (CWE)

CWE-639

References

FAQ

What is CVE-2026-42276?

CVE-2026-42276 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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...

How severe is CVE-2026-42276?

CVE-2026-42276 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42276?

Check the references section above for vendor advisories and patch information. Affected products include: Onyx Onyx.