Information Disclosure in Onyx (CVE-2026-71424)
Summary
Vulnerability in Onyx (CVE-2026-71424). Confidential information can be exposed externally. Exploitable via GET /api/mcp/servers.
Original description
The description as published by the source.
Onyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-71424 has been found in Onyx.
Attackers can target a specific entry point like GET /api/mcp/servers over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.6/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Onyx CVE-2026-71424" on the vendor's site.
CVE-2026-71424 (Onyx) — CWE-200 / CVSS v3 9.6
Attack vector: remote (network-reachable) / no user interaction
Attack surface: GET /api/mcp/servers / GET /api/mcp/servers/persona/{persona_id} / Authorization header
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in Onyx. Attackers reach the vulnerable code path via GET /api/mcp/servers.
Check the vendor advisory for the affected versions of Onyx. Attack surface: GET /api/mcp/servers / GET /api/mcp/servers/persona/{persona_id} / Authorization header.
Severity: Critical (CVSS 9.6/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/mcp/servers requests with malformed payloads or SQL meta-characters. Run grep -r 'Onyx' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Onyx' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Onyxを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /api/mcp/servers' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/mcp/serversへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against GET /api/mcp/servers on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- web github.com