WP Captcha PRO <= 5.38 — Authenticated (Subscriber+) Authentication Bypass via Temporary Login Link

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Advanced Google reCAPTCHA.
• No admin access? Run a passive check of your site. It reads public files only.

What to do

1. Update to version 5.39, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Advanced Google reCAPTCHA to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Nguyen Ngoc Duc (duc193).

The WP Captcha PRO (the premium version of the Advanced Google reCAPTCHA plugin, both have the same slug) plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.38. This is due to the ajax_run_tool() AJAX handler relying solely on a nonce check (check_ajax_referer) for security without performing any capability check, combined with the create_temporary_link tool allowing the generation of passwordless login links for arbitrary users, and the handle_temporary_links() function authenticating visitors via these links without any additional authorization validation. The required nonce is exposed to all authenticated backend users (including Subscribers) via wp_localize_script() on all non-settings admin pages when the plugin's welcome pointer has not been dismissed. This makes it possible for authenticated attackers, with Subscriber-level access and above, to bypass normal authentication and log in as any user, including Administrators, resulting in complete account takeover.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Jun 5, 2026

   CVE published

   Severity high, CVSS 8.8

2. Nov 13, 2026

   Record last updated