Debian has not fixed CVE-2021-44142
security-tracker.debian.orgDebian stable repositories currently serve version 4.13.13. Multiple security releases have been issued by samba since then: from 4.13.14 to the recent 4.13.17 which fixes CVE-2021-44142 [1].
It seems the current maintainer does not have any more time to work on the package [2].
[1] https://www.samba.org/samba/history/security.html
[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=814382