Changelog.md

 This page is used to log service changes.
 
+## 16 January 2023
+
+* Upgraded to GitLab 15.7.3. See the [Gitlab 15.7.3 release announcement](https://about.gitlab.com/releases/2022/12/22/gitlab-15-7-released/) for information on the release update and [Gitlab 15.7.3 release announcement](https://about.gitlab.com/releases/2023/01/11/gitlab-15-7-3-released/) for information on the security update.
+
 ## 2 December 2022
 
 * Upgraded to GitLab 15.5.5. See the [Gitlab 15.5.5 security release announcement](https://about.gitlab.com/releases/2022/11/30/security-release-gitlab-15-6-1-released/) for information on this update.