Sendmail 8.9.0 through 8.12.6 allows remote attackers to bypass relaying restrictions enforced by the 'checkrelay' function by spoofing a blank DNS hostname.

Sendmail before 8.10.0 allows remote attackers to cause a denial of service by sending a series of ETRN commands then disconnecting from the server, while Sendmail continues to process the commands after the connection has been terminated.

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.

Buffer overflow in Sendmail 5.79 to 8.12.7 allows remote attackers to execute arbitrary code via certain formatted address fields, related to sender and recipient header comments as processed by the crackaddr function of headers.c.