AVideo Vulnerable to Remote Code Execution via MIME/Extension Mismatch in ImageGallery File Upload

Exploitation

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

CVSS

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

EPSS

• CVE-2026-33647: 0.65% estimated exploitation activity in the next 30 days; percentile 51.24 (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 ImageGallery::saveFile() method validates uploaded file content using finfo MIME type detection but derives the saved filename extension from the user-supplied original filename without an allowlist check. An attacker can upload a polyglot file (valid JPEG magic bytes followed by PHP code) with a .php extension. The MIME check passes, but the file is saved as an executable .php file in a web-accessible directory, achieving Remote Code Execution. Details The vulnerability exists in plugin/ImageGallery/ImageGallery.php in the saveFile() method: Root cause: Line 93 extracts the extension from the user-supplied $file['name'] and uses it directly in the saved filename. There is no check against an allowlist of safe extensions (e.g., jpg, png, gif, webp, mp4). Why the MIME check is insufficient: PHP's finfo with FILEINFOMIMETYPE inspects file content magic bytes. A file starting with JPEG magic bytes (\xff\xd8\xff\xe0) is identified as image/jpeg regardless of trailing content.…

Published by the source

25 Mar 2026, 17:45 UTC

Last modified by the source

25 Mar 2026, 17:45 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wxjw-phj6-g75w

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# Patch Next advisory brief: CVE-2026-33647

Advisory: AVideo Vulnerable to Remote Code Execution via MIME/Extension Mismatch in ImageGallery File Upload
IDs: CVE-2026-33647, GHSA-wxjw-phj6-g75w
Record: https://patchnext.com/advisories/cve-2026-33647 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
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 <= 26.0

## 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-wxjw-phj6-g75w (GitHub-reviewed advisory GHSA-wxjw-phj6-g75w lists affected ranges: Packagist wwbn/avideo >=0 <=26.0)

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