# ACF Frontend Admin by DynamiApps <= 3.30.1 - Unauthenticated Limited File Upload via File Upload Field

- **ID:** WPSEC-2026-2252
- **Plugin:** ACF Frontend Admin by DynamiApps (`acf-frontend-form-element`), https://wordpress.org/plugins/acf-frontend-form-element/
- **Affected versions:** all versions before 3.30.2
- **Fixed in:** 3.30.2 (Update to 3.30.2 or later.)
- **Severity:** High 7.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-434
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-03)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/acf-frontend-form-element
- **Fix released:** 2026-11-01
- **Published:** 2026-11-03
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2252/

## Description

The ACF Frontend Admin by DynamiApps plugin for WordPress is vulnerable to limited file uploads via the 'acf/fields/upload_file/add_attachment' AJAX action in all versions up to, and including, 3.30.1. This is due to the file type check in validate_attachment() only running when the uploaded file name has an extension, so a file without an extension skips the allowed type check. The upload folder was also served without an X-Content-Type-Options: nosniff header. This makes it possible for unauthenticated attackers to upload files without an extension to the public fea-submissions uploads folder when a form with a file field is shown on the site. On servers that send such files without a content type, browsers may render them as HTML, which can lead to stored cross-site scripting.

## References

- https://wpsec.com/vuln/WPSEC-2026-2252/
- https://plugins.svn.wordpress.org/acf-frontend-form-element/tags/3.30.2/
- https://wordpress.org/plugins/acf-frontend-form-element/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2252/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.