The Pearl – Header Builder plugin for WordPress suffers from a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input in the 'stm_hb' shortcode. This flaw allows authenticated users with contributor or higher privileges to inject arbitrary JavaScript code into pages, which executes in the context of users visiting those pages. The vulnerability affects all versions up to and including 1.3.6. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, requiring privileges, no user interaction, and impacts on confidentiality and integrity but not availability. No patch or official fix has been documented in the provided data.

An attacker with contributor-level access or higher can exploit this vulnerability to inject malicious scripts that execute in the browsers of users who view the compromised pages. This can lead to unauthorized actions performed on behalf of users, theft of sensitive information, or session hijacking. The impact affects confidentiality and integrity but does not affect availability. Since the vulnerability requires authenticated access, the risk is limited to environments where such user roles exist.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict contributor-level access to trusted users only and consider disabling or removing the Pearl – Header Builder plugin if possible. Monitor for updates from the vendor and apply patches promptly once released.