Nettalk, an opensource IRC client available for Windows, was updated to version 6.6.4.
The main reason behind this update was a bug that has been found in version 6.5.6 of the client: a crash that can be triggered from remote using CTCP messages.
Whenever the first character of a message is an ASCII 1 the client crashes. According to Ntalk author Mirici the bug can not be exploited to cause more harm than the client crashing but he has released a fixed version of it.
Other reasons why users of Nettalk might want to upgrade is the “improved DCC function that is much faster compared to other clients” and the “improved and fixed handling of Chinese character handling using both UTF-8 and ASCII”.
Thanks go to Elmaron for the tip and Mirici for quickly fixing the bug!