Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints (CVE-2026-85700) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-85700

Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints

Answer in brief

CVE-2026-85700 records a Unknown severity vulnerability in Onyx 4.6.6 Custom Tool Secret Header Disclosure via Tool Endpoints. The current sources do not mark it as known exploited. The current feed maps onyx-dot-app/onyx (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 4, 2026Updated Sep 4, 2026Source checked Sep 4, 2026First seen by HOL Sep 4, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps onyx-dot-app/onyx (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
onyx-dot-app/onyxgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for onyx-dot-app/onyx.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 4, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.