Most notable with this new Debian 12 stable point release is picking up a new version of the Linux 6.2 LTS kernel as well as the latest linux-firmware/microcode support. Most notably this means picking up the mitigations for the AMD Inception (SRSO) vulnerability made public in August as well as the Intel Downfall vulnerability also made public in August.
Plus the updates in Debian 12.2 also have a range of other security fixes incorporated. The list of package updates found in Debian 12.2 and the security fixes can be found via the release announcement on Debian.org .