GitLab CE 8.17 and later and EE 8.3 and later have a symlink time-of-check-to-time-of-use race condition that would allow unauthorized acce…

GitLab CE 8.17 and later and EE 8.3 and later have a symlink time-of-check-to-time-of-use race condition that would allow unauthorized access to files in the GitLab Pages chroot environment. This is fixed in versions 11.5.1, 11.4.8, and 11.3.11.