fastify fastify-static up to 10.1.1 Path Normalization allowedPath path traversal

Summaryinfo

A vulnerability, which was classified as problematic, has been found in fastify fastify-static up to 10.1.1. This affects the function allowedPath of the component Path Normalization. Performing a manipulation of the argument allowedPath results in path traversal. This vulnerability is reported as CVE-2026-7120. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in fastify fastify-static up to 10.1.1. This affects the function allowedPath of the component Path Normalization. The manipulation of the argument allowedPath with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. This is going to have an impact on confidentiality. The summary by CVE is:

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolution. Versions up to and including 10.1.1 are affected. An unauthenticated attacker can bypass allowedPath restrictions by requesting equivalent non-canonical pathnames, causing files that were intended to be denied to be served anyway. The bypass does not allow access outside the configured static root by itself, it defeats path-based filtering only. The issue is patched in @fastify/static 10.1.2.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-7120 since 04/26/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

Upgrading to version 10.1.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at CNNVD (CNNVD-2026-79541213) and EUVD (EUVD-2026-47870). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• fastify

Name

• fastify-static

Version

• 10.1.0
• 10.1.1

Website

• Product: https://github.com/fastify/fastify-static/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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