This update for irssi fixes the following security issues:

- CVE-2018-7054: Use after free when server is disconnected during netsplits
- CVE-2018-7053: Use after free when SASL messages are received in unexpected order
- CVE-2018-7050: Null pointer dereference when an "empty" nick has been observed
- CVE-2018-7052: When the number of windows exceed the available space, Irssi would crash due to Null pointer dereference
- CVE-2018-7051: Certain nick names could result in out of bounds access when printing theme strings