CVE-2025-67364 Efforthye CVE debrief

Who should care

Defenders responsible for fast-filesystem-mcp deployments, security teams, and vulnerability management teams should assess exposure and prioritize verification and remediation to prevent unauthorized file access. This includes verifying affected versions, assessing potential impact, and implementing compensating controls for exposed systems.

Why it matters

CVE-2025-67364 is a critical path traversal vulnerability in fast-filesystem-mcp version 3.4.0 that allows attackers to bypass directory access restrictions. Defenders should prioritize verification and remediation to prevent unauthorized file access.

• Verify and update fast-filesystem-mcp to a secure version to prevent unauthorized file access
• Restrict access to sensitive files to limit potential damage
• Monitor for suspicious activity to detect potential exploitation

Technical summary

The fast-filesystem-mcp version 3.4.0 contains a critical path traversal vulnerability in its file operation tools, including fast_read_file. This vulnerability arises from improper path validation that fails to resolve symbolic links to their actual physical paths, allowing attackers to bypass directory access restrictions and access unauthorized files. The vulnerability impacts fast-filesystem-mcp deployments and defenders should prioritize verifying and updating fast-filesystem-mcp to a secure version, restricting access to sensitive files, and monitoring for suspicious activity.

Defensive priority

Defenders should prioritize verifying and updating fast-filesystem-mcp to a secure version, restricting access to sensitive files, and monitoring for suspicious activity.

Recommended defensive actions

• Verify and update fast-filesystem-mcp to a secure version
• Restrict access to sensitive files
• Monitor for suspicious activity
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions and retest remediated assets
• Confirm whether affected product deployments exist in managed environments

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, including its description, CVSS score, and affected versions. The vulnerability has been publicly disclosed and defenders should verify the affected versions and assess exposure. The CVE record was published on 2026-01-07T17:16:01.723Z and has not been modified since then. The official CVE Program record and NVD detail page offer source-provided CVE metadata and vulnerability assessment.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.