Auth bypass in Onyx
CVE-2026-42277
Onyx is an open-source AI platform. Prior to versions 3.0.9, 3.1.6, and 3.2.6, the GET /chat/file/{file_id} endpoint allows any authenticated user to download any other user's uploaded files by providing the file UUID. The endpoint verifies the caller is authenticated but never checks that the file belongs to them. An attacker who knows or obtains a file UUID can access confidential documents, chat attachments, and other files uploaded by any user in the system. This issue has been patched in versions 3.0.9, 3.1.6, and 3.2.6.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (25.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Onyx
- Onyx-Dot-App Onyx — versions < 3.0.9, >= 3.1.0, < 3.1.6, >= 3.2.0, < 3.2.6
Weakness classification (CWE)
References
- github.com/onyx-dot-app/onyx/security/advisories/GHSA-vg3h-35f7-7w6r (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42277?
- CVE-2026-42277 is a medium-severity vulnerability in Onyx, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-05-08.
- How severe is CVE-2026-42277?
- Medium severity. CVSS v3 base score is 6.5 out of 10.