The Post Carousel & Slider plugin for WordPress suffers from a stored XSS vulnerability due to improper neutralization of input during web page generation. Specifically, the plugin fails to adequately sanitize and escape user input in the 'post-cs' shortcode attributes, allowing authenticated contributors or higher to inject arbitrary JavaScript code. This code executes in the context of any user who views the compromised page, potentially leading to session hijacking or other script-based attacks. The vulnerability affects all versions up to and including 1.0.3.

An attacker with contributor-level access or above can inject persistent malicious scripts into pages using the vulnerable shortcode. These scripts execute in the browsers of users who visit the affected pages, potentially compromising user sessions or performing other unauthorized actions within the context of the site. The vulnerability does not affect availability but impacts confidentiality and integrity to a limited extent.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict contributor-level access to trusted users only and consider disabling or removing the Post Carousel & Slider plugin if possible. Monitor official sources for updates or patches addressing this vulnerability.