CVE-2025-11819 is a stored cross-site scripting vulnerability in the WP-Thumbnail plugin for WordPress, specifically in the 'roboshot' shortcode. The issue arises from improper neutralization of user-supplied input due to insufficient sanitization and output escaping of shortcode attributes. This allows authenticated users with contributor or higher privileges to inject arbitrary web scripts that execute in the context of any user viewing the compromised page. The vulnerability affects all versions up to and including 1.1. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, required privileges at the contributor level, no user interaction, and impacts on confidentiality and integrity with scope change.

An attacker with contributor-level access or higher can exploit this vulnerability to inject persistent malicious scripts into pages via the 'roboshot' shortcode. These scripts execute in the browsers of users who visit the infected pages, potentially leading to unauthorized actions such as session hijacking or data theft limited to the confidentiality and integrity impact as per the CVSS vector. There is no indication of availability impact. The vulnerability does not require user interaction beyond visiting the affected page.

No official patch or remediation has been provided yet for this vulnerability. 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 WP-Thumbnail plugin if possible to prevent exploitation.