CVE-2026-55582— mcp-shell: Secure Mode Allowlist Bypass via Git Shell Alias
Quick assessment
Affected
sonirico mcp-shell
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
mcp-shell 是一个 MCP 服务器，用于安全、可审计且按需地执行 shell 命令。在版本 0.6.0 之前，默认的 security.yaml 允许使用 /usr/bin/git，而 security.go 中缺少对 containsShellMetacharacters 和 containsDangerousShellConstructs 函数的感叹号（!）排除逻辑，并且未实施针对每个可执行文件的参数策略。调用 shell_exec MCP 工具的用户可以提供命令参数 /usr/bin/git -c a
Possible ATT&CK Techniques 2 AI
T1203 · Exploitation for Client Execution T1059 · Command and Scripting Interpreter
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I. Basic Information for CVE-2026-55582
Vulnerability Information
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Vulnerability Title
mcp-shell: Secure Mode Allowlist Bypass via Git Shell Alias
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
OS命令中使用的特殊元素转义处理不恰当(OS命令注入)
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-55582
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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Qwen3.6-35B-A3B
· 8835 chars
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III. Intelligence Information for CVE-2026-55582
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Patches & Fixes for CVE-2026-55582 (2)
Vendor Advisories for CVE-2026-55582 (1)
Vendor Pages for CVE-2026-55582 (1)
Same Patch Batch · sonirico · 2026-08-25 · 3 CVEs total
| CVE-2026-55580 | 8.6 HIGH | mcp-shell — Security Disabled by Default in Bare-Binary Deploy Path + Shell Interpreter in |
| CVE-2026-55581 | 8.4 HIGH | mcp-shell: Secure Mode Allowlist Bypass via Default `/bin/bash` Executable |
IV. Related Vulnerabilities
V. Comments for CVE-2026-55582
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