CVE-2026-44542: Gtsteffaniak Filebrowser Quantum

Critical severity, CVSS 9.1. EPSS: 0.6% chance of exploitation in the next 30 days.

FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-stable and 1.3.9-beta, attacker-controlled path input is joined with a trusted base path prior to sanitization, allowing traversal sequences (e.g., ../) to escape the intended shared directory. As a result, an unauthenticated attacker possessing a valid public share hash with delete permissions enabled can delete arbitrary files outside the shared directory within the share owner’s configured storage scope. This affects public/api/resources and public/api/resources/bulk. This vulnerability is fixed in 1.3.1-stable and 1.3.9-beta.

Affected products

• Gtsteffaniak Filebrowser Quantum: before 1.3.1 (fixed in 1.3.1); before 1.3.9 (fixed in 1.3.9)

Published 2026-05-14. Last modified 2026-06-17.