{"id":"CVE-2026-42276","aliases":["EUVD-2026-28524","GHSA-rw6w-hp62-gc8w"],"status":"published","title":"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.","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00279,"percentile":0.20475,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-639"],"published":"2026-05-08T03:49:56Z","modified":"2026-10-28T02:31:07Z","products":[{"vendor":"onyx","product":"onyx"},{"vendor":"onyx-dot-app","product":"onyx"}],"references":[{"url":"https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-rw6w-hp62-gc8w","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42276.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42276","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-42276","title":"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.","status":"published","published":"2026-05-08T03:49:56.765Z","modified":"2026-05-08T12:57:18.681Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T13:40:35.004553Z"}],"euvd":[{"id":"EUVD-2026-28524","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.","status":"published","published":"2026-05-08T03:49:56Z","modified":"2026-05-08T12:57:18Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T19:05:14.505765Z"}],"nvd":[{"id":"CVE-2026-42276","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.","status":"published","published":"2026-05-08T05:16:10.557Z","modified":"2026-06-17T10:47:37.107Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T14:12:17.842772Z"}],"osv":[{"id":"CVE-2026-42276","title":"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.","status":"published","published":"2026-05-08T03:49:56.765Z","modified":"2026-10-28T02:31:07.011316309Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T15:45:04.117819Z"}]}}