PT-2026-47627 · Gtsteffaniak+1 · Filebrowser+1

Published

2026-05-22

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Updated

2026-06-16

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CVE-2026-48777

CVSS v4.0

9.3

Critical

VectorAV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Name of the Vulnerable Software and Affected Versions FileBrowser Quantum versions prior to 1.3.3-stable FileBrowser Quantum versions prior to 1.4.2-beta
Description Path Traversal is possible through the publicPatchHandler function in backend/http/public.go. The issue occurs because the software joins user-controlled fromPath and toPath body fields with the trusted d.share.Path before the downstream sanitizer runs. Since filepath.Join collapses .. segments during this process, the sanitizer in resourcePatchHandler does not detect the traversal, allowing move, copy, or rename operations on paths outside the shared directory.
An unauthenticated attacker with a public share link where AllowModify=true can exploit this to move, copy, or rename arbitrary files within the share owner's source root. This can lead to the exfiltration of private files by renaming them into the shared directory or tampering with files the share owner has write access to.
Recommendations Update to version 1.3.3-stable. Update to version 1.4.2-beta. As a temporary workaround, restrict the use of public share links with AllowModify=true until the update is applied.

Fix

Path traversal

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Weakness Enumeration

Related Identifiers

CVE-2026-48777
GHSA-QQQM-5547-774X

Affected Products

Filebrowser
Github.Com/Gtsteffaniak/Filebrowser/Backend