CVE-2026-79534: n/a
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.
CVE-2026-79534: n/a
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.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-08-25T00:00:00.000Z
- State
- PUBLISHED
Threat ID: 6abc13a2680226ef682f7f22
Added to database: 09/29/2026, 19:38:10 UTC
Last updated: 09/29/2026, 19:38:10 UTC
Views: 1
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