# Contact Form by Supsystic <= 1.10.7 - Authenticated (Administrator+) Remote Code Execution via Server-Side Template Injection

- **ID:** WPSEC-2026-1520
- **Plugin:** Contact Form by Supsystic – Drag & Drop Form Builder with Templates & Form Statistics (`contact-form-by-supsystic`), https://wordpress.org/plugins/contact-form-by-supsystic/
- **Affected versions:** all versions before 1.11.1
- **Fixed in:** 1.11.1 (Update to 1.11.1 or later.)
- **Severity:** High 7.2 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H)
- **Weakness:** CWE-1336
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-23)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/contact-form-by-supsystic
- **Fix released:** 2026-10-22
- **Published:** 2026-10-23
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1520/

## Description

The Contact Form by Supsystic plugin for WordPress is vulnerable to Server-Side Template Injection in all versions up to, and including, 1.10.7 due to form template parameters and tag values being concatenated directly into Twig templates that were rendered without a sandbox. This makes it possible for authenticated attackers with administrator-level access to execute arbitrary code on the server, which is significant in environments where administrators cannot otherwise modify code, such as multisite installations or sites with file modifications disabled.

## References

- https://wpsec.com/vuln/WPSEC-2026-1520/
- https://plugins.svn.wordpress.org/contact-form-by-supsystic/tags/1.11.1/
- https://wordpress.org/plugins/contact-form-by-supsystic/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1520/

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.