The NEX-Forms – Ultimate Forms Plugin for WordPress contains a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input during web page generation. Specifically, the submit_nex_form() function does not adequately sanitize or escape POST parameter key names, enabling unauthenticated attackers to inject malicious scripts. These scripts are stored and executed in the context of users visiting the injected pages. The vulnerability affects all versions up to and including 9.1.11. The CVSS v3.1 base score is 7.2, indicating high severity with network attack vector, low attack complexity, no privileges required, no user interaction, and impacts on confidentiality and integrity with scope changed.

Successful exploitation allows unauthenticated attackers to perform stored cross-site scripting attacks, potentially leading to the execution of arbitrary scripts in the context of users visiting the affected pages. This can result in the theft of sensitive information, session hijacking, or other malicious actions impacting confidentiality and integrity. Availability is not affected. No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider disabling or restricting access to the vulnerable functionality or applying web application firewall (WAF) rules to detect and block suspicious POST requests targeting the submit_nex_form() function. Monitor vendor channels for updates and apply official patches promptly once available.