CVE-2026-54090 File Browser: Command Allowlist Bypass via Shell Metacharacter Injection
Attackers can execute arbitrary commands by injecting shell metacharacters when a shell interpreter is configured, bypassing the command allowlist.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54090?
CVE-2026-54090 is a high-severity command injection vulnerability in filebrowser, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.33.8, when a shell interpreter is configured (e.g. /bin/sh -c), the command allowlist can be bypassed through shell metacharacters. The allowlist validates only the first token of user input, but the entire raw string is handed to the shell — semicolons, pipes, backticks, and $() all work to chain arbitrary commands after a permitted one. This vulnerability is fixed in 2.33.8.
Which versions are affected by CVE-2026-54090?
4 open source packages ship an affected version, including github.com/filebrowser/filebrowser/v2 and github.com/filebrowser/filebrowser.
| Package | Affected | Fixed in |
|---|---|---|
github.com/filebrowser/filebrowser/v2 Go | All versions | 2.33.8 |
github.com/filebrowser/filebrowser/v2 Go | All versions | 2.33.8 |
github.com/filebrowser/filebrowser/v2 Go | All versions | 2.33.8 |
github.com/filebrowser/filebrowser Go | All versions | None |
How do I fix CVE-2026-54090?
Upgrade github.com/filebrowser/filebrowser/v2 to 2.33.8 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-54090 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54090 exists.
Sources
Also known as GHSA-8c9q-7855-wfxq, GO-2026-5250.