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OpenAdvisories
High · 8.6 CVE-2026-55580 EUVD-2026-65550GHSA-f5pj-2738-996mGO-2026-6292

mcp-shell — Security Disabled by Default in Bare-Binary Deploy Path + Shell Interpreter in Secure-Mode Allowlist

Published Aug 25, 2026 · Updated Aug 25, 2026 · Assigned by GitHub_M

Description

mcp-shell is an MCP server for running shell commands securely, auditably, and on demand. Prior to 0.6.0, config.go initializes Security.Enabled to false, and when MCP_SHELL_SEC_CONFIG_FILE is unset, main.go starts the documented bare-binary deployment without a security policy. SecurityValidator.validateCommand in security.go then short-circuits and allows every command supplied to the shell_exec MCP tool, so an LLM connected over stdio can execute unrestricted OS commands as the mcp-shell process user. The README from-source installation and MCP client configuration omit MCP_SHELL_SEC_CONFIG_FILE, making the insecure state the documented default. This issue is fixed in version 0.6.0.

Affected products

VendorProductAffectedFixed
sonirico mcp-shell < 0.6.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
SLES for SAP 16.0 govulncheck-vulndb 0.0.20260827T195228-160000.1.1 SUSE-SU-2026:23625-1
SLES 16.0 govulncheck-vulndb 0.0.20260827T195228-160000.1.1 SUSE-SU-2026:23625-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260827T195228-160000.1.1 openSUSE-SU-2026:21761-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/sonirico/mcp-shell < 0.6.0 0.6.0 GHSA-f5pj-2738-996m

Advisories 2

References