Description
The Contact Form by Supsystic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via IP Address Header in all versions up to, and including, 1.10.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. An unauthenticated attacker can first call the 'updateNonce' action — which is accessible without authentication due to its absence from the plugin's permission list — to obtain a valid nonce, then submit a contact form with a malicious payload in a spoofed IP header such as X-Forwarded-For.
References10
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
- plugins.trac.wordpress.org/browser/contact-form-by-supsystic/ta…
Metrics
- CVSS 3.1
-
7.2
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 1% percentile: 48 · as of 7 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.