The target's backtrace indicates that libc has detected a heap error or that the target was executing a heap function when it stopped. This could be due to heap corruption, passing a bad pointer to a heap function such as free(), etc. Since heap errors might include buffer overflows, use-after-free situations, etc. they are generally considered exploitable.

https://huntr.dev/bounties/20ece512-c600-45ac-8a84-d0931e05541f
https://github.com/vim/vim/commit/cc762a48d42b579fb7bdec2c614636b830342dd5