Irssi before 1.0.8, 1.1.x before 1.1.3, and 1.2.x before 1.2.1, when SASL is enabled, has a use after free when sending SASL login to the server.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. There is a use-after-free when a server is disconnected during netsplits. NOTE: this issue exists because of an incomplete fix for CVE-2017-7191.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. There is a use-after-free when SASL messages are received in an unexpected order.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. When the number of windows exceeds the available space, a crash due to a NULL pointer dereference would occur.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. Certain nick names could result in out-of-bounds access when printing theme strings.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. A NULL pointer dereference occurs for an "empty" nick.

In Irssi before 1.0.6, a calculation error in the completion code could cause a heap buffer overflow when completing certain strings.

When using an incomplete variable argument, Irssi before 1.0.6 may access data beyond the end of the string.

When the channel topic is set without specifying a sender, Irssi before 1.0.6 may dereference a NULL pointer.

When using incomplete escape codes, Irssi before 1.0.6 may access data beyond the end of the string.

In Irssi before 1.0.5, overlong nicks or targets may result in a NULL pointer dereference while splitting the message.

In certain cases, Irssi before 1.0.5 may fail to verify that a Safe channel ID is long enough, causing reads beyond the end of the string.

In Irssi before 1.0.5, certain incorrectly formatted DCC CTCP messages could cause a NULL pointer dereference. This is a separate, but similar, issue relative to CVE-2017-9468.

Irssi before 1.0.5, when installing themes with unterminated colour formatting sequences, may access data beyond the end of the string.

Irssi before 1.0.5, while waiting for the channel synchronisation, may incorrectly fail to remove destroyed channels from the query list, resulting in use-after-free conditions when updating the state later on.