The smcloseonexec function in conf.c in sendmail before 8.14.9 has arguments in the wrong order, and consequently skips setting expected FDCLOEXEC flags, which allows local users to access unintended high-numbered file descriptors via a custom mail-delivery program.

Sendmail before 8.13.7 allows remote attackers to cause a denial of service via deeply nested, malformed multipart MIME messages that exhaust the stack during the recursive mime8to7 function for performing 8-bit to 7-bit conversion, which prevents Sendmail from delivering queued messages and might lead to disk consumption by core dump files.

Signal handler race condition in Sendmail 8.13.x before 8.13.6 allows remote attackers to execute arbitrary code by triggering timeouts in a way that causes the setjmp and longjmp function calls to be interrupted and modify unexpected memory locations.