CVE-2026-71424

CRITICALPre-NVD 9.69.6—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 79% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.6Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.6
EG Score
9.6(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity96% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 18, 2026

Advisory Details (8)

Auto-updated Aug 29, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available🟡 PoC Available

Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers · Advisory · onyx-dot-app/onyx · GitHub

https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822
github_release Patch Available

v4.0.0

Patch available: onyx-dot-app/onyx v4.0.0

https://github.com/onyx-dot-app/onyx/releases/tag/v4.0.0
github_pr

fix: mcp oauth token handling (#11238) to release v3.1

Fix merged in onyx-dot-app/onyx PR #11243 on 2026-05-20 — awaiting tagged release

https://github.com/onyx-dot-app/onyx/pull/11243
github_pr

fix: mcp oauth token handling (#11238) to release v3.2

Fix merged in onyx-dot-app/onyx PR #11242 on 2026-05-20 — awaiting tagged release

https://github.com/onyx-dot-app/onyx/pull/11242
github_pr

fix: mcp oauth token handling

Fix merged in onyx-dot-app/onyx PR #11238 on 2026-05-20 — awaiting tagged release

https://github.com/onyx-dot-app/onyx/pull/11238
github_commit

commit b103937888fd (onyx-dot-app/onyx)

Fix landed in onyx-dot-app/onyx commit b103937888fd — awaiting tagged release

https://github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e5424576394f2
github_commit

commit 4001cedd0a89 (onyx-dot-app/onyx)

Fix landed in onyx-dot-app/onyx commit 4001cedd0a89 — awaiting tagged release

https://github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed56777910
github_commit

commit 3f3d79d1a772 (onyx-dot-app/onyx)

Fix landed in onyx-dot-app/onyx commit 3f3d79d1a772 — awaiting tagged release

https://github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d890017e9e

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 03:30 UTCEG score recompute
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-29 05:22 UTCEG score recompute
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 19:25 UTCEG score recompute
  6. 2026-08-26 15:08 UTCEG score recompute
  7. 2026-08-26 14:47 UTCEPSS rescore
  8. 2026-08-25 17:48 UTCEG score recompute
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-24 16:15 UTCEG score recompute
  11. 2026-08-24 11:56 UTCEG score recompute
  12. 2026-08-23 01:44 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 00:09 UTCEG score recompute
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-21 02:50 UTCEG score recompute
  17. 2026-08-20 22:56 UTCEPSS rescore
  18. 2026-08-19 20:11 UTCEG score recompute
  19. 2026-08-19 17:04 UTCEPSS rescore
  20. 2026-08-18 18:25 UTCEG score recompute
  21. 2026-08-18 18:00 UTCEG score recompute
  22. 2026-08-18 15:35 UTCEG score recompute
  23. 2026-08-18 13:49 UTCEPSS rescore
  24. 2026-08-18 13:49 UTCEPSS rescore
  25. 2026-08-17 22:22 UTCEG score recompute
Show 2 more
  1. 2026-08-17 21:40 UTCEG score recompute
  2. 2026-08-17 21:39 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-71424?
CVE-2026-71424 is a critical vulnerability published on August 17, 2026. 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/{personaid} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.settokens and OnyxTokenStorage.setclientinfo in…
When was CVE-2026-71424 disclosed?
CVE-2026-71424 was first published in the National Vulnerability Database on August 17, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-71424 actively exploited?
CVE-2026-71424 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.8% of all scored CVEs.
What is the CVSS score of CVE-2026-71424?
CVE-2026-71424 has a CVSS v3 base score of 9.6 (NVD).
How do I remediate CVE-2026-71424?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71424, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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