FlintSH Flare up to 1.7.2 Path Validation path.join path traversal

Summaryinfo

A vulnerability has been found in FlintSH Flare up to 1.7.2 and classified as critical. The impacted element is the function path.join of the component Path Validation Handler. Performing a manipulation results in path traversal. This vulnerability is known as CVE-2026-30942. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in FlintSH Flare up to 1.7.2. It has been classified as critical. This affects the function path.join of the component Path Validation Handler. The manipulation 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:

Flare is a Next.js-based, self-hostable file sharing platform that integrates with screenshot tools. Prior to 1.7.3, an authenticated path traversal vulnerability in /api/avatars/[filename] allows any logged-in user to read arbitrary files from within the application container. The filename URL parameter is passed to path.join() without sanitization, and getFileStream() performs no path validation, enabling %2F-encoded ../ sequences to escape the uploads/avatars/ directory and read any file accessible to the nextjs process under /app/. Authentication is enforced by Next.js middleware. However, on instances with open registration enabled (the default), any attacker can self-register and immediately exploit this. This vulnerability is fixed in 1.7.3.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-30942 since 03/07/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. 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 1.7.3 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch cd894cc480619aef958be5de72b1445222fd8d36 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• FlintSH

Name

• Flare

Version

• 1.7.0
• 1.7.1
• 1.7.2

License

• open-source

Website

• Product: https://github.com/FlintSH/Flare/

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