It wasn't available via `apt-get update && apt-get dist-upgrade` as of when I drafted that comment, but I confirm that 5.10.92-2 seems to be released now.

Well the fix was released ~30 minutes ago, so that checks out. ;-)

The security-tracker site is now updated as well.

Others, note that the new archive name is 'stable-security'. You might need to update your pins if you upgraded from Buster and you're not seeing the update now. I put in a pull request to add it to the release notes.