AVideo has an incomplete fix of CVE-2026-33482: sanitizeFFmpegCommand still allows a single '&' (background operator), giving OS command execution at the same execAsync sh -c sink

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-55173: 2.68% estimated exploitation activity in the next 30 days; percentile 85.83 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The fix for CVE-2026-33482 (GHSA-pmj8-r2j7-xg6c) is incomplete. That advisory reported that sanitizeFFmpegCommand() (plugin/API/standAlone/functions.php) failed to strip $(...) command substitution, allowing OS command injection at the execAsync() sh -c sink. The fix (commit 25c8ab90) added $, (, ), {, }, \n, \r to the denylist character class and a strreplace('&&', '', ...). It still does not neutralize a single & (the shell background operator), which remains a command separator at the unchanged sink. Same entry point, same sink, same impact as the original — only the surviving metacharacter differs. Verified at master HEAD. The surviving gap HEAD sanitizeFFmpegCommand (functions.php): A single & is therefore preserved. ffmpeg ... & <cmd passes the sanitizer and the strpos(trim($command),'ffmpeg')===0 prefix gate. Sink (unchanged) plugin/API/standAlone/ffmpeg.json.php:418 - execAsync($ffmpegCommand, $keyword). In objects/functionsExec.php::execAsync: The sanitized command…

Published by the source

23 Jun 2026, 17:42 UTC

Last modified by the source

23 Jun 2026, 17:42 UTC

Source last checked

26 Oct 2026, 14:49 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wc3f-xc32-435f

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# Patch Next advisory brief: CVE-2026-55173

Advisory: AVideo has an incomplete fix of CVE-2026-33482: sanitizeFFmpegCommand still allows a single '&' (background operator), giving OS command execution at the same execAsync sh -c sink
IDs: CVE-2026-55173, GHSA-wc3f-xc32-435f
Record: https://patchnext.com/advisories/cve-2026-55173 (revision 1, source checked 26 Oct 2026, 14:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist wwbn/avideo: affected <= 29.0

## Suggested inspection (read-only)
- Packagist wwbn/avideo: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on wwbn/avideo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wc3f-xc32-435f (GitHub-reviewed advisory GHSA-wc3f-xc32-435f lists affected ranges: Packagist wwbn/avideo >=0 <=29.0)

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