GitLab has remediated an issue in GitLab CE/EE affecting all versions from 19.1 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain conditions, could have allowed an authenticated user to execute arbitrary JavaScript in the context of other users' browser sessions via a specially crafted repository, due to improper sanitization of HTML attributes in syntax-highlighted output.