Expat, when used in a parser that has not called XML_SetHashSalt or passed it a seed of 0, makes it easier for context-dependent attackers to defeat cryptographic protection mechanisms via vectors involving use of the srand function.
https://security.gentoo.org/glsa/201701-21
https://www.tenable.com/security/tns-2016-20
http://www.debian.org/security/2016/dsa-3597
http://www.openwall.com/lists/oss-security/2016/06/03/8