CVE-2026-55582

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Source

https://cve.org/CVERecord?id=CVE-2026-55582

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55582.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-55582

Aliases

Published

2026-08-25T15:37:43.486Z

Modified

2026-08-30T03:30:37.147285742Z

Severity

8.4 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator

Summary

mcp-shell: Secure Mode Allowlist Bypass via Git Shell Alias

Details

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.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55582.json",
    "cwe_ids": [
        "CWE-78"
    ],
    "cna_assigner": "GitHub_M"
}

References

Affected packages

Git / github.com/sonirico/mcp-shell

Affected ranges

Type

GIT

Repo

https://github.com/sonirico/mcp-shell

Events

Introduced

Fixed

f31377fce6ec31114e5a4398c0e5270552bce09f

Fixed

df02c8c74044a950d5c085626da8de49c7551cd5

Database specific

Show details

{
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.6.0"
        }
    ]
}

Affected versions

v0.*

v0.1.0

v0.2.0

v0.2.2

v0.3.0

v0.3.1

v0.4.0

v0.5.0

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55582.json"