A AegiFlow
HIGHCVSS 8.4EPSS 0.3%

CVE-2026-55581

CVE-2026-55581 updated by NVD

Published
2026-08-25
Modified
2026-09-11
EPSS percentile
27%
Sources
github-advisory, nvd

Summary

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 `, 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.

Affected packages

EcosystemPackageAffected versionsFixed versions
Gogithub.com/sonirico/mcp-shell0.6.0

Remediation: Upgrade to 0.6.0 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

CVE® is a registered trademark of The MITRE Corporation. CVE content reproduced under the CVE Terms of Use; copyright designation © MITRE.

EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.