{"id":"CVE-2026-79534","title":"mark3labs mcp-filesystem-server v0.11.1 is vulnerable to Directory Traversal due to an improper link resolution in validatePath (filesystemserver/handler/helper.go)","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…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N","cwe":["CWE-22","CWE-59"],"published":"2026-09-29","updated":"2026-09-30","sourceUpdated":"2026-09-30T21:17:15.850","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-79534","references":[{"url":"https://www.traceforce.ai/security-advisories/cve-2026-79534","label":"cve@mitre.org"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-30T19:10:32.829309Z"},"epss":0.00194,"epssPercentile":0.09036,"ingestedAt":"2026-09-29T19:44:04.153Z","slug":"CVE-2026-79534","body":"## Overview\n\nmark3labs 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":214019,"id":"CVE-2026-79534","ts":1790803610071,"field":"cvss","old":null,"new":"5.9"},{"seq":214018,"id":"CVE-2026-79534","ts":1790803610071,"field":"severity","old":"none","new":"medium"}]}