Vulnerability in Simple CAPTCHA with Cloudflare Turnstile — CVE-2026-93900
What to do now
Update Simple CAPTCHA with Cloudflare Turnstile to 1.44.4 or later.
Affected versions
- Everything up to and including 1.44.3
Affected: Simple CAPTCHA with Cloudflare Turnstile (plugin, simple-cloudflare-turnstile)
What the vulnerability is
The Simple CAPTCHA with Cloudflare Turnstile plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' attribute of the [gravity-simple-turnstile] shortcode in versions up to, and including, 1.44.3 This is due to insufficient input sanitization and output escaping on the shortcode attribute in the cfturnstile_gravity_shortcode() function: the value is filtered only by esc_html() and sanitize_text_field() (neither of which touches parentheses or dots) and then emitted via esc_js() in a raw JavaScript expression context outside any string literal (esc_js only escapes quotes, backslashes, and newlines). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Sources
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.41.0/inc/integrations/forms/gravity-forms.php#L13
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.41.0/inc/integrations/forms/gravity-forms.php#L22
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.43.1/inc/integrations/forms/gravity-forms.php#L13
- https://plugins.trac.wordpress.org/browser/simple-cloudflare-turnstile/tags/1.43.1/inc/integrations/forms/gravity-forms.php#L22
- https://plugins.trac.wordpress.org/changeset/3776057/simple-cloudflare-turnstile/trunk/inc/integrations/forms/gravity-forms.php