CVE-2026-48777: critical vulnerability in gtsteffaniak filebrowser
FileBrowser Quantum: Path Traversal in public share PATCH allows file ops outside shared directory
Published · Updated
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 0.5%
exploitation probability
0.5%top 58% of all CVEs
observed exploitation
nono source reports it
FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted d.share.Path BEFORE the downstream sanitizer runs. Because filepath.Join collapses .. segments during the join, the sanitizer in resourcePatchHandler never sees the traversal and the move/copy/rename operates on a path outside the shared directory. The same root-cause pattern was patched for the bulk DELETE endpoint as CVE-2026-44542 (GHSA-fwj3-42wh-8673), but the PATCH handler with the identical pattern was not updated. A public share link with AllowModify=true is sufficient to exploit this. Anyone holding such a link can move, copy, or rename arbitrary files within the share owner's source root. This issue has been fixed in versions 1.3.3-stable and 1.4.2-beta.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
gtsteffaniak · filebrowserRelated CVEs — gtsteffaniak filebrowser
In the same product, most dangerous first.
CVE-2026-44542CRITICALFileBrowser Quantum: Unauthenticated Path Traversal in Public Share Delete Allows Arbitrary File DeletionEPSS 0.6%CVE-2026-30933HIGHFileBrowser Quantum Incomplete Remediation of CVE-2026-27611: Password-Protected Share Bypass via /public/api/share/infoEPSS 0.5%CVE-2026-54685MEDIUMFileBrowser Quantum has Username Enumeration via Authentication Timing Side-ChannelEPSS 0.5%CVE-2026-54910HIGHFileBrowser Quantum's path traversal issue in subtitle handler allows any authenticated user to read arbitrary filesEPSS 0.5%CVE-2026-46410HIGHFileBrowser Quantum: unauthenticated user share share infoEPSS 0.4%CVE-2026-27611HIGHFileBrowser Quantum: Password Protection Not Enforced on Shared File LinksEPSS 0.4%