GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.5 before 18.11.7, 19.0 before 19.0.4, and 19.1 before 19.1.2 that under certain conditions could have allowed an authenticated user to create a repository where the content displayed in the web interface differed from the content available for download, due to improper handling of Git reference name resolution.
Upgrade to versions 18.11.7, 19.0.4, 19.1.2 or above.