SEPTEMBER 18, 2026
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Case File

CVE-2026-55581

HIGH · CVSS 8.4 EPSS 0.34% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-25 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability affects the mcp-shell component of Docker, allowing unauthorized execution of arbitrary commands due to improper validation of the command-line arguments. An attacker can exploit this flaw by using the shell_exec MCP tool to execute commands as the mcpuser, bypassing the intended security restrictions. Organizations utilizing versions prior to 0.6.0 should prioritize patching to mitigate the risk of unauthorized command execution.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-55581
Severity
HIGH
CVSS
8.4
EPSS
0.34%
Docker

Original NVD Description

mcp-shell is an MCP server for running shell commands securely, auditably, and on demand. Prior to 0.6.0, the default Docker security.yaml includes /bin/bash in allowed_executables, while security.go validates only the first token and checkBlockedPatternsAndCommands does not reject the shell command-mode flag -c. A caller of the shell_exec MCP tool can provide the command argument `/bin/bash -c <arbitrary-command>`, which passes validation and reaches executor.go, where parseCommand and exec.CommandContext execute the arbitrary command as mcpuser outside the intended allowlist. This issue is fixed in version 0.6.0.