CVE-2026-4257 Scanner
CVE-2026-4257 Scanner - Server Side Template Injection (SSTI) vulnerability in WordPress Contact Form by Supsystic
Used 3.3k times · 4.2k assets checked · url
CVE
CVE-2026-4257
9.8
CVSScritical
Exploitable remotely over the internet · no authentication required.
Description
The Contact Form by Supsystic plugin for WordPress is vulnerable to Server-Side Template Injection (SSTI) leading to Remote Code Execution (RCE) in all versions up to, and including, 1.7.36. This is due to the plugin using the Twig `Twig_Loader_String` template engine without sandboxing, combined with the `cfsPreFill` prefill functionality that allows unauthenticated users to inject arbitrary Twig expressions into form field values via GET parameters. This makes it possible for unauthenticated attackers to execute arbitrary PHP functions and OS commands on the server by leveraging Twig's `registerUndefinedFilterCallback()` method to register arbitrary PHP callbacks.
Attack Vector
Network
Privileges Req.
None
User Interaction
None
contact form by supsystic
Updated Nov 6, 2026View on NVD →
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CVE history: contact form by supsystic
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