CVE-2026-42276

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

08/05/2026

Last modified:

12/05/2026

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&#39;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&#39;s LLM generation mid-stream. This issue has been patched in versions 3.0.9, 3.1.6, and 3.2.6.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 4.30 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

Base Score 3.x

4.30

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:onyx:onyx::::::::		3.0.9 (excluding)
cpe:2.3:a:onyx:onyx::::::::	3.1.0 (including)	3.1.6 (excluding)
cpe:2.3:a:onyx:onyx::::::::	3.2.0 (including)	3.2.6 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-42276

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools