VulnerabilityAnalyzed
CVE-2026-42276
An attacker who knows a chat session UUID can kill another user's LLM generation mid-stream.
MEDIUM 4.3EPSS 0.28%
Does this matter?
Lower severity and a low EPSS score (0.28%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- EPSS
- 0.28% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Affected
- onyx/onyx
- Source
- security-advisories@github.com
References
- https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8wExploit, Vendor Advisory
- https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8wExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.