/Vulnerability Library

argocd-mcp 0.8.0 - Unauthenticated MCP Session and Tool Access

CVE-2026-82456
Verified

Description

argocd-mcp before 0.9.0 binds its MCP HTTP listener to all interfaces without requiring authentication. A remote unauthenticated attacker can initialize an MCP session, complete the handshake, and enumerate or invoke the full Argo CD tool surface using the operator's stored API token.

Severity

Critical

CVSS Score

10

Exploit Probability

2%

Affected Product

mcp-for-argocd

Published Date

September 14, 2026

Template Author

kh1166

CVE-2026-82456.yaml
10.0Score

CVSS Metrics

CVSS Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVE ID:
cve-2026-82456
CWE ID:
cwe-306

References

https://github.com/argoproj-labs/mcp-for-argocd/security/advisories/GHSA-rp45-5x3v-48mrhttps://nvd.nist.gov/vuln/detail/CVE-2026-82456https://www.vulncheck.com/advisories/argocd-mcp-0.8.0-authentication-bypass-via-unauthenticated-httphttps://github.com/argoproj-labs/mcp-for-argocd/releases

Remediation Steps

Upgrade to argocd-mcp 0.9.0 and set MCP_AUTH_TOKEN so inbound callers must present an Authorization bearer header. Keep --bind-address on 127.0.0.1 unless an external auth layer is in front of the listener, and do not use --allow-unauthenticated to restore a wide bind.