CVE-2026-81094: mcp-router mcp-router

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

CVSS 9.3 CriticalCriticalEPSS 0.0061 · 49th percentile

Critical, because:

CVSS score 9.3: 9.0 or more.

Published by the CVE Program (CNA: VulnCheck) at 27 Aug 2026, 14:50 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
mcp-router	mcp-router https://github.com/mcp-router/mcp-router	affected before 0.6.3 semver unaffected 4c4642cfd274097ec8b33ecd3047390829c79d35 git Other versions: unaffected

Identifiers

CVE-2026-81094

CNA

VulnCheck

Weakness (CWE)

CWE-306

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.3	Critical	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N	CNA (VulnCheck)Used for this record
9.1	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0061, the 49th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 27 Aug 2026. New records show when each source confirmed them.

Sources

References from the CNA

github.com/mcp-router/mcp-router product
github.com/mcp-router/mcp-router/security/advisories/GHSA-rx55-5c7h-r56r vendor-advisory
github.com/mcp-router/mcp-router/commit/4c4642cfd274097ec8b33ecd3047390829c79d35 patch
github.com/mcp-router/mcp-router/blob/v0.6.3/apps/cli/src/commands/serve.ts#L105 technical-description
www.vulncheck.com/advisories/mcp-router-cli-before-0.6.3-binds-the-mcp-aggregator-to-all-interfaces-without-requiring-authentication third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.