CVE-2026-79534

medium

mark3labs mcp-filesystem-server v0.11.1 is vulnerable to Directory Traversal due to an improper link resolution in validatePath (filesystemserver/handler/helpe…

mark3labs mcp-filesystem-server v0.11.1 is vulnerable to Directory Traversal due to an improper link resolution in validatePath (filesystemserver/handler/helper.go). When filepath.EvalSymlinks returns os.IsNotExist for a dangling symlink, the fallback validates only the parent directory and returns the unresolved path, so write_file (and modify_file, copy_file, move_file, create_directory) follows a pre-existing dangling symlink located inside an allowed directory and creates a file outside the configured allowed directories.

CVSS

5.9

5.9 (CVSS v3.1)

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

Severity source: NVD CVSS v3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)

Timeline (UTC)

Published: 2026-09-29 20:17

Modified: 2026-09-30 21:17

NVD status: Deferred

Last synced 2 days ago

Verified against the source API 2026-10-27 06:56 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

Not reported by the source (unknown — not "none").

Weakness classification (CWE)

CWE-22 CWE-59

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

https://www.traceforce.ai/security-advisories/cve-2026-79534 cve@mitre.org

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:56 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores