FileBrowser Quantum: Password Protection Not Enforced on Shared File Links

Exploitation

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

CVSS 4.0

7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-27611: 0.37% estimated exploitation activity in the next 30 days; percentile 30.50 (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 When users share password-protected files, the recipient can completely bypass the password and still download the file. Details This happens because the API returns a direct download link in the details of the share, which is accessible to anyone with JUST THE SHARE LINK, even without the password. PoC 1. As an authenticated user, create a share for a file, with a password specified in "Optional password" (make sure to allow anonymous access as the PoC doesn't explain how to do this on a share that requires login, but it is also possible to do on a share that requires login, with some small tweaks to the API request) 2. Copy the first link (the clipboard WITHOUT an arrow) because the second one just completely skips the password without any effort required, which was mentioned in another vulnerability (https://github.com/filebrowser/filebrowser/security/advisories/GHSA-3v48-283x-f2w4) Now, the link that was copied should look like:…

Published by the source

25 Feb 2026, 16:00 UTC

Last modified by the source

27 Apr 2026, 14:56 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8vrh-3pm2-v4v6

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-27611

Advisory: FileBrowser Quantum: Password Protection Not Enforced on Shared File Links
IDs: CVE-2026-27611, GHSA-8vrh-3pm2-v4v6
Record: https://patchnext.com/advisories/cve-2026-27611 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
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 0.0.0-20260221163904-dbcfba993b85. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gtsteffaniak/filebrowser/backend: affected < 0.0.0-20260221163904-dbcfba993b85; fixed in 0.0.0-20260221163904-dbcfba993b85

## 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://github.com/advisories/GHSA-8vrh-3pm2-v4v6 (GitHub-reviewed advisory GHSA-8vrh-3pm2-v4v6 lists affected ranges: Go github.com/gtsteffaniak/filebrowser/backend >=0 <0.0.0-20260221163904-dbcfba993b85)

Commands are suggestions: review each one before running it.