# 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.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-8c9q-7855-wfxq, GO-2026-5250

## 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.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command), CWE-184 (Incomplete List of Disallowed Inputs)

## 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 | Ecosystem | 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.

## Is CVE-2026-54090 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54090 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54090 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54090 exists.

Affected packages and fixed versions:
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.33.8
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.33.8
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.33.8
- github.com/filebrowser/filebrowser (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54090/ (Markdown: https://insights.sbomify.com/CVE-2026-54090/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54090
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54090
- OSV: https://osv.dev/vulnerability/CVE-2026-54090

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54090/
Summaries are generated and may contain mistakes; the official description above is the record.