CVE-2026-55582

mcp-shell is an MCP server for running shell commands securely, auditably, and on demand. Prior to 0.6.0, the default security.yaml allows /usr/bin/git, while security.go omits ! from containsShellMetacharacters and containsDangerousShellConstructs and applies no per-executable argument policy. A caller of the shell_exec MCP tool can provide the command argument /usr/bin/git -c alias.pwn=!<arbitrary-command>, causing Git to create a shell alias and execute arbitrary OS commands as the mcp-shell process user. The default Docker image runs as mcpuser with Git installed and secure mode enabled, so the bypass is exploitable in the default deployment without additional authentication beyond MCP connectivity. This issue is fixed in version 0.6.0.

• CWE-78

• https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f
• https://github.com/sonirico/mcp-shell/pull/16
• https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0
• https://github.com/sonirico/mcp-shell/security/advisories/GHSA-74hp-mggr-hv58
• https://github.com/sonirico/mcp-shell/security/advisories/GHSA-74hp-mggr-hv58

Published

Aug 25, 2026

Last Modified

Sep 9, 2026

Status

Deferred

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-55577ImageMagick is free and open-source software used for editin…5.9
• CVE-2026-55578Pheditor is a single-file editor and file manager written in…8.8
• CVE-2026-55579Pheditor is a single-file editor and file manager written in…9.8
• CVE-2026-5558A flaw has been found in PHPGurukul PHPGurukul Online Shoppi…6.3
• CVE-2026-55580mcp-shell is an MCP server for running shell commands secure…8.6
• CVE-2026-55581mcp-shell is an MCP server for running shell commands secure…8.4
• CVE-2026-55583Twenty is an open-source CRM (customer relationship manageme…7.6
• CVE-2026-55584phpSysInfo is a customizable PHP script that displays system…7.5
• CVE-2026-55585QWED is open-source AI verification infrastructure for deter…8.8
• CVE-2026-55586SumatraPDF is a multi-format reader for Windows. In 3.6.1 an…6.6
• CVE-2026-55588ORAS (OCI Registry As Storage) is a CLI and library for mana…6.5
• CVE-2026-5559A vulnerability has been found in AntaresMugisho PyBlade 0.1…6.3