RCE in Efforthye Fast-Filesystem-Mcp
CVE-2026-5327
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.018 (77.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.018 · change: +0.006
Affected products
- Efforthye Fast-Filesystem-Mcp — versions 3.5.0, 3.5.1
Weakness classification (CWE)
References
- vuldb.com/vuln/354658 (technical-description, vdb-entry)
- vuldb.com/vuln/354658/cti (signature, permissions-required)
- vuldb.com/submit/780776 (third-party-advisory)
- github.com/efforthye/fast-filesystem-mcp/issues/15 (issue-tracking)
- github.com/user-attachments/files/25822878/fast-filesystem-mcp_bug.pdf (exploit)
- github.com/efforthye/fast-filesystem-mcp/ (product)
Frequently asked questions
- What is CVE-2026-5327?
- CVE-2026-5327 is a medium-severity vulnerability in Efforthye Fast-Filesystem-Mcp, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.3/10. Published 2026-04-02.
- How severe is CVE-2026-5327?
- Medium severity. CVSS v3 base score is 6.3 out of 10.