# CVE-2026-54090: File Browser command allowlist bypass via shell metacharacter injection

Source: https://junglewise.ai/threats/cve-2026-54090-file-browser-command-allowlist-bypass-via-shell-metacharacter  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-25. Updated: 2026-06-25  
License: CC BY 4.0 with a link back

CVE-2026-54090 · Severity: high · CVSS 4 · Published 2026-06-25

File Browser, a web-based file management interface, contains a vulnerability that allows users with limited command permissions to execute unauthorized commands on the server. By using special characters like semicolons or pipes, an attacker can bypass security restrictions to run arbitrary code, potentially taking full control of the server. This feature is now disabled by default in newer versions to protect users.

Technologies: [File Browser](https://junglewise.ai/threats/technologies/file-browser), [github.com/filebrowser/filebrowser (Go)](https://junglewise.ai/threats/technologies/github-com-filebrowser-filebrowser), [github.com/filebrowser/filebrowser/v2 (Go)](https://junglewise.ai/threats/technologies/github-com-filebrowser-filebrowser-v2). Vendors: [File Browser](https://junglewise.ai/threats/vendors/file-browser), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-54090 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54090 being exploited in the wild.

**How severe is CVE-2026-54090?** High severity, with a CVSS score of 4, published 25 June 2026.

**Which products and versions are affected?** File Browser < 2.33.8; github.com/filebrowser/filebrowser (Go) SEMVER:introduced=0; github.com/filebrowser/filebrowser/v2 (Go) < 2.33.8, SEMVER:introduced=0,fixed=2.33.8.

**Is there a fix for CVE-2026-54090?** Yes. github.com/filebrowser/filebrowser/v2 (Go): upgrade to 2.33.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54090 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-54090?** Check whether you run File Browser, github.com/filebrowser/filebrowser (Go) or github.com/filebrowser/filebrowser/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/filebrowser/filebrowser/v2 (Go): upgrade to 2.33.8 or later

  ```sh
  go get github.com/filebrowser/filebrowser/v2@v2.33.8
  ```


## Technical details

A command injection vulnerability exists in File Browser's command runner component due to improper neutralization of shell metacharacters. While the application validates the first token of user input against an allowlist, it subsequently passes the entire raw input string to the configured shell interpreter (e.g., /bin/sh -c). An authenticated attacker with 'Execute' permissions can use semicolons, pipes, or backticks to chain and execute arbitrary OS commands. This issue was addressed in version 2.33.8 by disabling the command execution feature by default; users must explicitly enable it and acknowledge the risks.

## Affected products

- filebrowser File Browser < 2.33.8

## Identifiers

- CVE-2026-54090
- GHSA-8c9q-7855-wfxq
- GO-2026-5250

## Timeline

- 2026-06-03: advisory: GitHub security advisory published
- 2026-06-25: disclosed: CVE-2026-54090 published

## References

- [https://github.com/filebrowser/filebrowser/issues/5199](https://github.com/filebrowser/filebrowser/issues/5199)
- [https://github.com/filebrowser/filebrowser/security/advisories/GHSA-8c9q-7855-wfxq](https://github.com/filebrowser/filebrowser/security/advisories/GHSA-8c9q-7855-wfxq)

## Related threats

- [File Browser symlink alias path traversal bypass](https://junglewise.ai/threats/cve-2026-90930-file-browser-symlink-alias-path-traversal-bypass)
- [File Browser authorization bypass in direct-upload endpoint](https://junglewise.ai/threats/cve-2026-90929-file-browser-authorization-bypass-in-direct-upload-endpoint)
- [File Browser subtitle conversion memory exhaustion](https://junglewise.ai/threats/cve-2026-90928-file-browser-subtitle-conversion-memory-exhaustion)
- [File Browser stale share link exposure in cross-user file deletion](https://junglewise.ai/threats/cve-2026-82236-file-browser-stale-share-link-exposure-in-cross-user-file)
- [File Browser path-based access control bypass in recursive operations](https://junglewise.ai/threats/cve-2026-73612-file-browser-path-based-access-control-bypass-in-recursive)