GHSA-9C87-P3CG-99HJ
Vulnerability from github – Published: 2026-09-29 21:33 – Updated: 2026-09-29 21:33mark3labs 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.
{
"affected": [],
"aliases": [
"CVE-2026-79534"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-29T20:17:26Z",
"severity": null
},
"details": "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.",
"id": "GHSA-9c87-p3cg-99hj",
"modified": "2026-09-29T21:33:26Z",
"published": "2026-09-29T21:33:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-79534"
},
{
"type": "WEB",
"url": "https://www.traceforce.ai/security-advisories/cve-2026-79534"
}
],
"schema_version": "1.4.0",
"severity": []
}
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