CVE-2026-81094

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-27. the CNA's CVSS baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 4 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

The mcp-router CLI served its MCP aggregator on every interface and enforced authentication only when the operator asked for it. The serve command in apps/cli/src/commands/serve.ts defaulted its host to the all-interfaces address on a fixed port, and required a token only when the corresponding flag was supplied, so a default invocation exposed the aggregator, and every MCP server it fronted, to anyone able to reach the port. Release 0.6.3 defaults the host to the loopback address and refuses to start without a token whenever the host it is given is not a loopback address; no earlier release carries either check.

CVSS v3
9.1
EG Score
9.1(high)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 29, 2026

Advisory Details (4)

Auto-updated Aug 29, 2026
Patch available. Sources: github_commit.
generic

mcp-router CLI before 0.6.3 Binds the MCP Aggregator to All Interfaces Without Requiring Authentication | Advisories | VulnCheck

https://www.vulncheck.com/advisories/mcp-router-cli-before-0.6.3-binds-the-mcp-aggregator-to-all-interfaces-without-requiring-authentication
generic

mcp-router/apps/cli/src/commands/serve.ts at v0.6.3 · mcp-router/mcp-router · GitHub

https://github.com/mcp-router/mcp-router/blob/v0.6.3/apps/cli/src/commands/serve.ts#L105
github_commit Patch Available

commit 4c4642cfd274 (mcp-router/mcp-router)

Patch available: mcp-router/mcp-router v0.6.3 (contains commit 4c4642cfd274)

https://github.com/mcp-router/mcp-router/commit/4c4642cfd274097ec8b33ecd3047390829c79d35
generic

GitHub - mcp-router/mcp-router: A Unified MCP Server Management App (MCP Manager). · GitHub

https://github.com/mcp-router/mcp-router

Vendor Advisories for CVE-2026-81094(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 25× in last 7d / 25× 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 05:11 UTCEG score recompute
  2. 2026-08-30 05:11 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-30 00:54 UTCGHSA enrichment
  5. 2026-08-29 20:37 UTCGHSA enrichment
  6. 2026-08-29 16:17 UTCGHSA enrichment
  7. 2026-08-29 11:59 UTCEG score recompute
  8. 2026-08-29 11:59 UTCGHSA enrichment
  9. 2026-08-29 08:30 UTCGHSA enrichment
  10. 2026-08-29 04:12 UTCGHSA enrichment
  11. 2026-08-28 23:54 UTCEG score recompute
  12. 2026-08-28 23:54 UTCGHSA enrichment
  13. 2026-08-28 21:42 UTCEPSS rescore
  14. 2026-08-28 18:01 UTCGHSA enrichment
  15. 2026-08-28 13:42 UTCGHSA enrichment
  16. 2026-08-28 09:24 UTCGHSA enrichment
  17. 2026-08-28 05:05 UTCGHSA enrichment
  18. 2026-08-28 00:44 UTCGHSA enrichment
  19. 2026-08-27 20:27 UTCEG score recompute
  20. 2026-08-27 20:27 UTCGHSA enrichment
  21. 2026-08-27 20:18 UTCEG score recompute
  22. 2026-08-27 20:18 UTCGHSA enrichment
  23. 2026-08-27 17:27 UTCEG score recompute
  24. 2026-08-27 16:47 UTCEG score recompute
  25. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-81094?
CVE-2026-81094 is a critical vulnerability published on August 27, 2026. The mcp-router CLI served its MCP aggregator on every interface and enforced authentication only when the operator asked for it. The serve command in apps/cli/src/commands/serve.ts defaulted its host to the all-interfaces address on a fixed port, and required a token only when the corresponding…
When was CVE-2026-81094 disclosed?
CVE-2026-81094 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81094 actively exploited?
CVE-2026-81094 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 64.9% of all scored CVEs.
What is the CVSS score of CVE-2026-81094?
CVE-2026-81094 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-81094?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81094, 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.

Dependency Blast Radius

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