Vulnerability in Onyx-Dot-App Onyx
CVE-2026-85700
Onyx 4.6.6 fails to properly restrict access to custom tool credentials stored in custom_headers, allowing any authenticated user to read admin-defined API keys. Attackers with basic authentication can call GET /tool/{tool_id} or GET /tool endpoints to retrieve plaintext authorization headers and third-party API credentials, then use them to directly access upstream APIs.
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: 0.005 (42.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
Weakness classification (CWE)
References
- github.com/onyx-dot-app/onyx (product)
- github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/api… (technical-description)
- github.com/onyx-dot-app/onyx/blob/v4.6.6/backend/onyx/server/features/tool/mode… (technical-description)
- github.com/onyx-dot-app/onyx/issues/13165 (issue-tracking)
- www.vulncheck.com/advisories/onyx-4.6.6-custom-tool-secret-header-disclosure-vi… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-85700?
- CVE-2026-85700 is a medium-severity vulnerability in Onyx-Dot-App Onyx, classified under Insufficiently Protected Credentials. CVSS score: 6.5/10. Published 2026-09-04.
- How severe is CVE-2026-85700?
- Medium severity. CVSS v3 base score is 6.5 out of 10.