CVE 2021-39939
An uncontrolled resource consumption vulnerability in GitLab Runner affecting all versions starting from 13.7 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2, allows an attacker triggering a job with a specially crafted docker image to exhaust resources on runner manager
See the
CVE page on Mitre.org
for more details.