CVE-2023-48706

Vim is a UNIX editor that, prior to version 9.0.2121, has a
heap-use-after-free vulnerability. When executing a :s command for the
very first time and using a sub-replace-special atom inside the
substitution part, it is possible that the recursive :s call causes
free-ing of memory which may later then be accessed by the initial :s
command. The user must intentionally execute the payload and the whole
process is a bit tricky to do since it seems to work only reliably for the
very first :s command. It may also cause a crash of Vim. Version 9.0.2121
contains a fix for this issue.