CVE-2026-16145

High

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.

SeverityHigh
CVSS7.2
Exploit probability—
ProductInvisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms
PublishedAug 15, 2026
First seenAug 15, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
matthiasnordwig Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Formsv ≤ 5.1—

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