CVE-2025-66401 is a critical-severity (CVSS 9.8) OS Command Injection vulnerability in mcp-watch. O3 Security confirms whether CVE-2025-66401 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MCP Watch has a Critical Command Injection in cloneRepo allows Remote Code Execution (RCE) via malicious URL
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
mcp-watchnpmDescription
MCP Watch is a comprehensive security scanner for Model Context Protocol (MCP) servers. In 0.1.2 and earlier, the MCPScanner class contains a critical Command Injection vulnerability in the cloneRepo method. The application passes the user-supplied githubUrl argument directly to a system shell via execSync without sanitization. This allows an attacker to execute arbitrary commands on the host machine by appending shell metacharacters to the URL.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mcp-watch | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mcp-watch. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of mcp-watch has shipped for CVE-2025-66401 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-66401 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-66401. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-66401 in your dependencies?
O3 detects CVE-2025-66401 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.