The NEX-Forms – Ultimate Forms Plugin for WordPress contains a stored cross-site scripting vulnerability identified as CVE-2026-13040. This vulnerability exists in all versions up to and including 9.2.2 and is due to improper neutralization of input in the 'real_val__' parameter. The plugin's submission endpoint, registered via wp_ajax_nopriv_submit_nex_form, does not implement nonce verification, allowing unauthenticated attackers to inject arbitrary web scripts that execute when users access the affected pages. The CVSS 3.1 base score is 7.2, indicating a high severity with network attack vector, low attack complexity, no privileges required, no user interaction, and impacts on confidentiality and integrity with scope changed.

An unauthenticated attacker can exploit this vulnerability to inject and store malicious scripts that execute in the context of users visiting the affected pages. This can lead to theft of sensitive information, session hijacking, or other malicious actions impacting confidentiality and integrity. There is no impact on availability. The vulnerability affects all users who access the injected content.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to the vulnerable plugin or disable it if possible. Monitor for updates from the vendor and apply patches promptly once released.