The mikakaltoft Horizontal Line Shortcode plugin suffers from a stored cross-site scripting vulnerability due to improper input neutralization during web page generation. This flaw allows an attacker with low privileges and requiring user interaction to inject malicious scripts that can compromise confidentiality, integrity, and availability to a limited extent. The vulnerability affects all versions up to 1.0. No vendor advisory or patch information is provided, and the plugin is not a cloud service, so remediation depends on the vendor releasing an update.

Successful exploitation could allow an attacker to execute arbitrary scripts in the context of other users, potentially leading to information disclosure, session hijacking, or other impacts on confidentiality, integrity, and availability. The CVSS vector indicates network attack vector, low attack complexity, requiring privileges and user interaction, with partial impact on confidentiality, integrity, and availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should consider restricting access to trusted users only and avoid using the vulnerable plugin if possible. Monitor official vendor channels for updates or patches addressing this vulnerability.