CVE-2026-5327
CVE-2026-5327 is a CWE-74 vulnerability in fast-filesystem-mcp. O3 Security confirms whether CVE-2026-5327 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
efforthye fast-filesystem-mcp index.ts handleGetDiskUsage command injection
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
fast-filesystem-mcpnpmDescription
A security flaw has been discovered in efforthye fast-filesystem-mcp up to 3.5.1. The affected element is the function handleGetDiskUsage of the file src/index.ts. Performing a manipulation results in command injection. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | fast-filesystem-mcp | 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 fast-filesystem-mcp. 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 fast-filesystem-mcp has shipped for CVE-2026-5327 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-2026-5327 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-2026-5327. 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-2026-5327 in your dependencies?
O3 detects CVE-2026-5327 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.