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TI-2026-55107 Aliases CVE-2026-79534GHSA-9c87-p3cg-99hj

mark3labs mcp-filesystem-server v0.11.1 is vulnerable to Directory Traversal due to an…

Priority LOW 26CWE-22Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00194 9th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-79534
  2. 2026-10-03 Alias added: GHSA-9c87-p3cg-99hj

References

Other 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences