Summary
@modelcontextprotocol/server-filesystem allows for path validation bypass via prefix matching and symlink handling
Versions of Filesystem prior to 0.6.3 & 2025.7.1 could allow access to unintended files via symlinks within allowed directories. Users are advised to upgrade to 2025.7.1 to resolve.
Thank you to Elad Beber (Cymulate) for reporting these issues.
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-53109? CVE-2025-53109 is a high-severity security vulnerability in @modelcontextprotocol/server-filesystem (npm), affecting versions <= 0.6.2. It is fixed in 2025.7.1.
- Which versions of @modelcontextprotocol/server-filesystem are affected by CVE-2025-53109? @modelcontextprotocol/server-filesystem (npm) versions <= 0.6.2 is affected.
- Is there a fix for CVE-2025-53109? Yes. CVE-2025-53109 is fixed in 2025.7.1. Upgrade to this version or later.
- Is CVE-2025-53109 exploitable, and should I be worried? Whether CVE-2025-53109 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-53109 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-53109? Upgrade
@modelcontextprotocol/server-filesystemto 2025.7.1 or later.