The makers of IDA disassembly and debugging tool have fixed more than a dozen security vulnerabilities in a variety of versions. Some of the vulnerabilities are a couple of years old, and patches are provided for versions from 6.1 up through 6.6.1. The oldest vulnerability is a flaw in the WinDbg debugger module that was disclosed in April 2011. There’s also a vulnerability in the mach-o loader triggered by a specially crafted input file that s fixed in IDA 6.4.
Source: https://threatpost.com/big-batch-of-bugs-fixed-in-various-versions-of-ida/108263/