File Browser versions from 2.50.0 through 2.63.21 fail to validate JWT expiration when proxy authentication is configured with a non-default logout page. Attackers with a previously valid token can access protected routes and administrative endpoints indefinitely, and exchange expired tokens for fresh ones via the renewal endpoint.
https://www.vulncheck.com/advisories/file-browser-through-jwt-expiration-bypass
https://github.com/filebrowser/filebrowser/security/advisories/GHSA-v3jv-rmh2-635j
https://github.com/filebrowser/filebrowser/commit/72faf6dd3c85628e332d3e567124b86708ce2695
Published: 2026-08-13
Updated: 2026-08-14
Base Score: 6.6
Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:N
Severity: Medium
Base Score: 6.8
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Severity: Medium
Base Score: 7.6
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00266