FileBrowser Quantum's path traversal issue in subtitle handler allows any authenticated user to read arbitrary files

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

EPSS

• CVE-2026-54910: 0.38% estimated exploitation activity in the next 30 days; percentile 31.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The subtitlesHandler endpoint (GET /api/media/subtitles) accepts two user-controlled query parameters: path and name, both of which are used in filesystem operations without sanitization, creating two independent path traversal vectors. The primary vector is the path parameter: it is passed directly to idx.GetRealPath() without calling SanitizeUserPath(), allowing an attacker to escape the storage root and set parentDir to any directory on the host. No existing anchor file is required. The secondary vector is the name parameter: it is joined with parentDir via filepath.Join(parentDir, name) without stripping directory components, allowing traversal relative to any resolved parentDir. Any authenticated user (regardless of role or permissions) can exploit either vector to read any text file readable by the server process, including /etc/passwd, SSH keys, database credentials, and JWT signing keys. Details 1. path parameter lacks SanitizeUserPath() — primary vector…

Published by the source

31 Jul 2026, 22:35 UTC

Last modified by the source

18 Aug 2026, 15:00 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vvp7-h4fj-m28w

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6164

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-vvp7-h4fj-m28w

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# Patch Next advisory brief: CVE-2026-54910

Advisory: FileBrowser Quantum's path traversal issue in subtitle handler allows any authenticated user to read arbitrary files
IDs: CVE-2026-54910, GHSA-vvp7-h4fj-m28w
Record: https://patchnext.com/advisories/cve-2026-54910 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/gtsteffaniak/filebrowser/backend 0.0.0-20260608182036-f3f4bbe80cb5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gtsteffaniak/filebrowser/backend: affected < 0.0.0-20260608182036-f3f4bbe80cb5; fixed in 0.0.0-20260608182036-f3f4bbe80cb5

## Suggested inspection (read-only)
- Go github.com/gtsteffaniak/filebrowser/backend: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/gtsteffaniak/filebrowser/backend.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-vvp7-h4fj-m28w (OSV record GHSA-vvp7-h4fj-m28w lists affected ranges: Go github.com/gtsteffaniak/filebrowser/backend >=0 <0.0.0-20260608182036-f3f4bbe80cb5 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6164 (OSV record GO-2026-6164 lists affected ranges: Go github.com/gtsteffaniak/filebrowser/backend >=0 <0.0.0-20260608182036-f3f4bbe80cb5 (fixed))
- Verified: https://github.com/advisories/GHSA-vvp7-h4fj-m28w (GitHub-reviewed advisory GHSA-vvp7-h4fj-m28w lists affected ranges: Go github.com/gtsteffaniak/filebrowser/backend >=0 <0.0.0-20260608182036-f3f4bbe80cb5)

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