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TI-2026-81497 Aliases CVE-2026-116682GHSA-mgqf-5mf5-prfj

Symlink following in FileBrowser Quantum exposes out-of-scope files

Priority HIGH 76CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-22 and the CVSS impact.

Summary

FileBrowser Quantum before 1.5.2-stable, and from 2.0.0-beta before 2.0.1-beta, follows symbolic links during file reads without checking that the target stays inside the source root and the user's authorized scope. An authenticated user with download access can read server-accessible files outside their assigned scope. A holder of a public share link can do the same without an account when the shared directory contains such a symlink. The flaw is tracked as CWE-59.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

Description from the CNA

FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.5.2-stable and 2.0.1-beta, file read handling in backend/pkg/indexing/indexingFiles.go resolves symbolic links through GetRealPath without confirming that the resolved target remains inside the source root and the user's authorized scope. Download, preview, media, OnlyOffice, and public-share read flows that enable FollowSymlinks can therefore serve an out-of-scope target through a reachable in-scope symlink. An authenticated user with download access can read server-accessible files outside the assigned scope, and a holder of a public share link can do the same without an account when the shared directory exposes such a symlink. This issue is fixed in 1.5.2-stable and 2.0.1-beta.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00536 45th percentileScored 2026-11-07
Fix Fixed filebrowser (gtsteffaniak): 1.5.2-stable, 2.0.1-betagithub.com/gtsteffaniak/filebrowser/backend (Go): 0.0.0-20260814233832-4126edeb07a0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
gtsteffaniakfilebrowserbefore 1.5.2-stable; 2.0.0-beta to before 2.0.1-beta1.5.2-stable, 2.0.1-betaPatch availableCNA
—github.com/gtsteffaniak/filebrowser/backend (Go)before 0.0.0-20260814233832-4126edeb07a00.0.0-20260814233832-4126edeb07a0Patch availableGHSA-mgqf-5mf5-prfj
  • filebrowser Vendorgtsteffaniak Affected before 1.5.2-stable; 2.0.0-beta to before 2.0.1-beta Fixed in 1.5.2-stable, 2.0.1-beta Patch available CNA
  • github.com/gtsteffaniak/filebrowser/backend (Go) Vendor— Affected before 0.0.0-20260814233832-4126edeb07a0 Fixed in 0.0.0-20260814233832-4126edeb07a0 Patch available GHSA-mgqf-5mf5-prfj

Remediation

Upgrade FileBrowser Quantum to 1.5.2-stable or 2.0.1-beta, the versions that fix the issue. Go projects that import github.com/gtsteffaniak/filebrowser/backend should update to 0.0.0-20260814233832-4126edeb07a0.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

  • Fix · CNA filebrowser (gtsteffaniak) Fixed in 1.5.2-stable, 2.0.1-beta
  • Fix · GHSA-mgqf-5mf5-prfj github.com/gtsteffaniak/filebrowser/backend (Go) Fixed in 0.0.0-20260814233832-4126edeb07a0 Advisory →

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-116682
  2. 2026-10-27 Alias added: GHSA-mgqf-5mf5-prfj
  3. 2026-10-28 Priority changed: MEDIUM → LOW
  4. 2026-11-02 CISA SSVC decision points changed
  5. 2026-11-02 Priority changed: LOW → HIGH

References

Advisory 1

Other 8

  • TI-2026-36047 FileBrowser Quantum: Path Traversal in public share PATCH allows file ops outside shared directory CVSS 4.0CRITICAL 9.3
  • TI-2026-32454 FileBrowser Quantum: Unauthenticated Path Traversal in Public Share Delete Allows Arbitrary File Deletion CVSS 3.1CRITICAL 9.1
  • TI-2026-23759 FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse) CVSS 3.1HIGH 8.9
  • TI-2026-23758 FileBrowser Quantum Incomplete Remediation of CVE-2026-27611: Password-Protected Share Bypass via /public/api/share/info CVSS 3.1HIGH 7.5
  • TI-2026-21997 FileBrowser Quantum: Password Protection Not Enforced on Shared File Links CVSS 4.0HIGH 7.1
  • TI-2026-39682 FileBrowser Quantum's path traversal issue in subtitle handler allows any authenticated user to read arbitrary files CVSS 3.1HIGH 7.7
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences