# CVE-2026-108953: mac-shell-mcp before 2.0.0 OS Command Injection via execute_command Arguments

> Attackers can execute arbitrary shell commands by injecting metacharacters into arguments, bypassing whitelists in mac-shell-mcp.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** GHSA-ffv7-8x5h-5w7r

## What is CVE-2026-108953?

CVE-2026-108953 is a high-severity command injection vulnerability in cfdude mac-shell-mcp, published on 12 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

mac-shell-mcp before 2.0.0 contains an OS command injection vulnerability that allows MCP clients to bypass the command whitelist by injecting shell metacharacters into execute_command arguments. Attackers or malicious prompts can call a safe command such as pwd with arguments like ';' to run forbidden commands as the server user without approval.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-108953?


## How do I fix CVE-2026-108953?

No fix has been published for CVE-2026-108953 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-108953 being exploited?

There is no known exploitation of CVE-2026-108953 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-108953 and fix it if it is affected.

What it is: CVE-2026-108953 is a high-severity command injection vulnerability in cfdude mac-shell-mcp, published on 12 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-108953 in the wild and no public exploit code.

Affected product: cfdude mac-shell-mcp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-108953/ (Markdown: https://insights.sbomify.com/CVE-2026-108953/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-108953
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-108953
- OSV: https://osv.dev/vulnerability/CVE-2026-108953

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-108953/
Summaries are generated and may contain mistakes; the official description above is the record.