GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.7 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 with Developer role to execute CI/CD pipelines on protected branches without authorization due to improper authorization checks in the downstream pipeline creation service.
Upgrade to versions 19.2.8, 19.3.5, 19.4.2 or above.