CVE-2026-44542: FileBrowser Quantum: Unauthenticated Path Traversal in Public Share Delete Allows Arbitrary File Deletion

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-14 · updated 2026-10-25
Weakness: CWE-22

Description

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: before 1.3.1; before 1.3.9 — fixed in 1.3.1, 1.3.9

How to fix

Upgrade to a fixed version: gtsteffaniak filebrowser 1.3.1, 1.3.9. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-44542 or the next vulnerability affects your stack