Improper sanitization of branch names in GitLab Runner affecting all versions prior to 15.3.5, 15.4 prior to 15.4.4, and 15.5 prior to 15.5.2 allows a user who creates a branch with a specially crafted name and gets another user to trigger a pipeline to execute commands in the runner as that other user.

For GitLab Runner before 13.0.12, 13.1.6, 13.2.3, by replacing dockerd with a malicious server, the Shared Runner is susceptible to SSRF.