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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-55581 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/sonirico/mcp-shell/commit/f31377fce6ec31114e5a4398c0e5270552bce09f GitHub, Inc.
https://github.com/sonirico/mcp-shell/pull/16 GitHub, Inc.
https://github.com/sonirico/mcp-shell/releases/tag/v0.6.0 GitHub, Inc.
https://github.com/sonirico/mcp-shell/security/advisories/GHSA-3x77-wg38-92r3 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') GitHub, Inc.  
CWE-183 Permissive List of Allowed Inputs GitHub, Inc.  
CWE-1188 Insecure Default Initialization of Resource GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-55581
NVD Published Date:
08/25/2026
NVD Last Modified:
08/25/2026
Source:
GitHub, Inc.