# File Browser has a Command Execution Allowlist Bypass via Shell Metacharacter Injection

Advisory record · `GHSA-8c9q-7855-wfxq`

- **Identifiers:** `GHSA-8c9q-7855-wfxq` · `CVE-2026-54090` · `GO-2026-5250`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-77](https://cwe.mitre.org/data/definitions/77.html) · [CWE-184](https://cwe.mitre.org/data/definitions/184.html)
- **Tags:** [Command injection](https://agentprime.io/advisories/tag/command-injection.md) · [CWE-184](https://agentprime.io/advisories/tag/cwe-184.md)
- **Published:** 12 Jun 2026
- **Updated:** 21 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 12 Jun 2026, 22:52 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/filebrowser/filebrowser/v2` (Go): affected `<2.33.8`; fixed in `2.33.8`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Affected: File Browser (github.com/filebrowser/filebrowser/v2) before 2.33.8. The command execution allowlist checks only the first token of user input, but the full string is passed to a configured shell, so shell metacharacters such as semicolons or pipes let a user chain arbitrary commands. An attacker needs an account with Execute permission and at least one allowed command, and the administrator must have enabled command execution with a shell configured. Upgrade to 2.33.8 or later. Command execution is disabled by default from 2.33.8 onward.

Written 6 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.7 High, CVSS 4.0: `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`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0044, the 38th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:05 UTC: First seen by agentprime
- 31 Oct 2026, 15:05 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-8c9q-7855-wfxq)

## Sources

- [GitHub Advisory Database: GHSA-8c9q-7855-wfxq](https://github.com/advisories/GHSA-8c9q-7855-wfxq)
- [OSV: GHSA-8c9q-7855-wfxq](https://osv.dev/vulnerability/GHSA-8c9q-7855-wfxq)
- <https://github.com/filebrowser/filebrowser/security/advisories/GHSA-8c9q-7855-wfxq>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-54090>
- <https://github.com/filebrowser/filebrowser/issues/5199>
- <https://github.com/filebrowser/filebrowser>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-8c9q-7855-wfxq>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-8c9q-7855-wfxq/>. Everything for agents: <https://agentprime.io/llms.txt>.