CVE-2026-93900 Simple CAPTCHA with Cloudflare Turnstile <= 1.44.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

Description

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.

Exploitable remotely over the network, with an ordinary account and without any user action; the impact on data or service is limited.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected products and versions