CVE-2026-61459 -- CVSS 9.8 Vulnerability Briefing

CVE-2026-61459 | CVSS 9.8 (Critical) | Exploit: PoC available

What Is It

CVE-2026-61459 is a critical argument injection vulnerability in Suyogs Mcp-Server-Kubernetes versions before 3.9.0, affecting the structured kubectl_get, kubectl_describe, and kubectl_delete tools.

Technical Detail

The affected tools do not adequately prevent resourceType and name parameter values beginning with dashes from being interpreted as kubectl command-line flags, allowing attackers to bypass the assertNoDangerousFlags check. An attacker can inject a --server argument that redirects kubectl requests to an attacker-controlled Kubernetes API server. If successful, the MCP server operator's Kubernetes bearer token can be sent to that external server, potentially allowing unauthorized cluster access and full cluster compromise.

Exploitation Status

A proof of concept is available. CISA has not listed this vulnerability in the Known Exploited Vulnerabilities catalog, and active exploitation in the wild has not been confirmed.

Who Is Targeting This

No specific threat actor attribution at this time.

What To Do

Upgrade Suyogs Mcp-Server-Kubernetes to version 3.9.0 or later as a priority. Until patching is complete, restrict access to MCP structured tools to trusted users and workflows, validate or reject resourceType and name inputs that begin with hyphens, and prevent the MCP server host from reaching untrusted Kubernetes API endpoints. Review Kubernetes API server and proxy logs for kubectl requests directed to unexpected server addresses, and rotate potentially exposed Kubernetes bearer tokens or service account credentials if suspicious outbound connections or unauthorized API activity are identified.