The SVG Support WordPress plugin versions before 2.5.17 fail to sanitize uploaded files with the .svgz extension. Although these files are registered and served as SVGs, the lack of sanitization allows users with SVG upload permissions to upload script-bearing .svgz files. Such files can execute scripts in the browsers of users who view them, including administrators. This vulnerability has a CVSS score of 6.1, indicating a medium severity level.