Yesterday, Samsung released the September 2023 security update, and that update is now available for the Galaxy S23 series. The new security update is currently rolling out to the carrier-locked versions of Galaxy S23 series phones in the US.
The newest software update for the Galaxy S23, Galaxy S23+, and Galaxy S23 Ultra comes with firmware version S91xUSQS1AWHD for the carrier-locked units in the US. The update is currently rolling out on Verizon's network in the US. Other carriers could also release the new update on their networks soon. As per Samsung's documentation, the September 2023 security patch fixes 62 security flaws found in the previous version of the software.
Looking at the firmware version, it looks like the update only brings the new security patch and nothing else. So, don't expect to see any new features or performance improvements with the new software update.
If you have a carrier-locked Galaxy S23 series phone in the US, you can now check for the new update on your phone. To do that, navigate to Settings » Software update and tap Download and install. Once the firmware becomes available in our firmware database, you can download it and flash it using a computer running Windows OS and the Odin tool.