CVE-2026-79534 json
mark3labs mcp-filesystem-server v0.11.1 is vulnerable to Directory Traversal due to an improper link resolution in validatePath (filesystem…
published 2026-09-29 41 d ago modified 2026-09-30 39 d ago also EUVD-2026-89359
- cvss
- 5.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 39 d ago
Exploit prediction
0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 5.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N |
| CNA | 3.1 | 5.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N |
Classification
References
Sources
- CVE List CVE-2026-79534
- NVD CVE-2026-79534
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