Gitlab v16 security updates

after reading GitLab Patch Release: 17.3.1, 17.2.4, 17.1.6 | GitLab i feel that i should upgrade my v16.11, because releases from 8.2 are affected. but there are no security fixes mentioned for v16.11.

according to GitLab release and maintenance policy | GitLab and given that 17.3 is the current stable release, the two previous monthly releases would be 17.2 and 17.1, which means 16.11 is now unsupported?

Correct.

Helpful upgrade resources are collected in GitLab Upgrade Path Resources