Vulnerability · Published Aug 15, 2026 · Assigned by Wordfence

CVE-2026-16145Invisible Anti-Spam & CAPTCHA <= 5.1 - Unauthenticated Stored Cross-Site Scripting via 'action' Parameter

High 7.2

In plain English

A high-severity cross-site scripting in Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms from matthiasnordwig. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).

Severity (CVSS 3.1)7.2High

Exploit odds (30 days)0.5%top 59.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'action' parameter in all versions up to, and including, 5.1 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. The stored payload is written by any unauthenticated admin-ajax.php request whose action value matches an entry in the plugin's explicit-actions list, which is auto-populated for common form builders at activation and requires no authentication gate to reach the save path.

Affected products (as reported)

Vendor	Product	Versions
matthiasnordwig	Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms	0 – through 5.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

In plain English

Official description

Affected products (as reported)

References