Description
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.
Published: 2026-09-29
Score: 5.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Wed, 30 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-59
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 30 Sep 2026 05:00:00 +0000

Type Values Removed Values Added
Title Directory Traversal via Dangling Symlink in mark3labs mcp-filesystem-server
Weaknesses CWE-22

Tue, 29 Sep 2026 19:45:00 +0000

Type Values Removed Values Added
Description 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.
References

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-30T20:11:11.005Z

Reserved: 2026-08-25T00:00:00.000Z

Link: CVE-2026-79534

cve-icon Vulnrichment

Updated: 2026-09-30T19:09:48.578Z

cve-icon NVD

Status : Deferred

Published: 2026-09-29T20:17:26.993

Modified: 2026-09-30T21:17:15.850

Link: CVE-2026-79534

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-30T04:45:19Z

Weaknesses
  • CWE-22

    Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

  • CWE-59

    Improper Link Resolution Before File Access ('Link Following')