Exim before 4.95 has a heap-based buffer overflow for the alias list in host_name_lookup in host.c when sender_host_name is set.
https://www.openwall.com/lists/oss-security/2022/08/06/8
https://www.exim.org/static/doc/security/
https://lists.debian.org/debian-lts-announce/2022/08/msg00014.html
https://github.com/ivd38/exim_overflow
https://github.com/Exim/exim/wiki/EximSecurity
https://github.com/Exim/exim/compare/exim-4.94...exim-4.95
https://github.com/Exim/exim/commit/d4bc023436e4cce7c23c5f8bb5199e178b4cc743