CVE-2025-13849 is a stored cross-site scripting vulnerability in the Cool YT Player WordPress plugin by matiasanca, affecting all versions up to 1.0. The issue is due to improper neutralization of input during web page generation, specifically insufficient sanitization and escaping of the 'videoid' parameter. This allows authenticated users with Contributor-level privileges or higher to inject arbitrary web scripts that execute in the context of other users viewing the injected pages. The vulnerability has a CVSS score of 6.4 (medium severity) with network attack vector, low attack complexity, and no user interaction required. There is no indication of known exploits in the wild or an available patch at this time.

An attacker with Contributor-level access or higher can exploit this vulnerability to inject malicious scripts that execute in other users' browsers when they access the compromised pages. This can lead to theft of user credentials, session hijacking, or other actions permitted by the victim's browser context. The impact is limited to confidentiality and integrity with no direct availability impact. The vulnerability requires authenticated access, which limits the attack surface to users with some level of trust on the site.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, site administrators should restrict Contributor-level access to trusted users only and consider disabling or replacing the Cool YT Player plugin to prevent exploitation. Monitoring for suspicious activity related to injected scripts may help detect exploitation attempts.