CVE-2026-42276
Onyx: IDOR in /chat/stop-chat-session allows any authenticated user to interrupt other users chat sessions
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.
INFO
Published Date :
May 8, 2026, 5:16 a.m.
Last Modified :
May 12, 2026, 2:08 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Onyx to version 3.0.9 or later.
- Update Onyx to version 3.1.6 or later.
- Update Onyx to version 3.2.6 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42276.
| URL | Resource |
|---|---|
| https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w | Exploit Vendor Advisory |
| https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42276 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42276
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42276 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42276 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 12, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:onyx:onyx:*:*:*:*:*:*:*:* versions up to (excluding) 3.0.9 *cpe:2.3:a:onyx:onyx:*:*:*:*:*:*:*:* versions from (including) 3.1.0 up to (excluding) 3.1.6 *cpe:2.3:a:onyx:onyx:*:*:*:*:*:*:*:* versions from (including) 3.2.0 up to (excluding) 3.2.6 Added Reference Type CISA-ADP: https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 08, 2026
Action Type Old Value New Value Added Reference https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w -
New CVE Received by [email protected]
May. 08, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-639 Added Reference https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w