Sylius is an open source eCommerce platform. In versions prior to 1.9.10, 1.10.11, and 1.11.2, it is possible to upload an SVG file containing cross-site scripting (XSS) code in the admin panel. In order to perform a XSS attack, the file itself has to be open in a new card or loaded outside of the IMG tag.

The problem applies both to the files opened on the admin panel and shop pages. The issue is fixed in versions 1.9.10, 1.10.11, and 1.11.2. As a workaround, require a library that adds on-upload file sanitization and overwrite the service before writing the file to the filesystem.

The GitHub Security Advisory contains more specific information about the workaround.