A vulnerability has been found and corrected in xmlsec1:
A missing check for the recommended minimum length of the truncated
form of HMAC-based XML signatures was found in xmlsec1 prior to
1.2.12. An attacker could use this flaw to create a specially-crafted
XML file that forges an XML signature, allowing the attacker to
bypass authentication that is based on the XML Signature specification
This update fixes this vulnerability...