CVE-2026-15964 britcoder CVE debrief

Who should care

WordPress site administrators, security teams, and users of the Single Sign On For TNG plugin should be aware of this critical vulnerability and take immediate action to protect their sites.

Technical summary

The Single Sign On For TNG plugin for WordPress is vulnerable to Authentication Bypass via unauthenticated password reset in all versions up to, and including, 2.0.0. This is due to the `ssoprocess_ajax()` function — registered on `wp_ajax_nopriv_ssoprocess_ajax` and therefore reachable without authentication — accepting an attacker-supplied `email` parameter with the `setnewpassword` operation and calling `reset_password()` on the resolved account without any ownership token, email confirmation link, or capability check.

Defensive priority

CVE-2026-15964 is a critical vulnerability in the Single Sign On For TNG plugin for WordPress, allowing unauthenticated attackers to bypass authentication and change the password of any WordPress account, including administrator accounts, enabling complete site takeover. The vulnerability has a CVSS score of 9.8 and is classified as CRITICAL.

Recommended defensive actions

• Inventory and verify the Single Sign On For TNG plugin version on all WordPress installations
• Apply the latest security patches and updates for the Single Sign On For TNG plugin
• Implement additional security measures, such as monitoring and incident response planning
• Consider replacing the plugin with a more secure alternative
• Restrict access to sensitive areas of the WordPress site

Evidence notes

The vulnerability is caused by the `ssoprocess_ajax()` function, which accepts an attacker-supplied `email` parameter with the `setnewpassword` operation and calls `reset_password()` on the resolved account without any ownership token, email confirmation link, or capability check. The sole guard is a call to `check_ajax_referer()`, which provides no authorization barrier because the `ssoajaxnonce` nonce is publicly broadcast on every front-end page via `wp_localize_script()` into the `SSOPWDREQUIREMENT` JavaScript object.

Official resources