This patch fixes CVE-2019-12400
In version 2.0.3 Apache Santuario XML Security for Java, a caching
mechanism was introduced to speed up creating new XML documents using a
static pool of DocumentBuilders. However, if some untrusted code can
register a malicious implementation with the thread context class loader
first, then this implementation might be cached and re-used by Apache
Santuario - XML Security for Java, leading to potential security flaws
when validating signed documents, etc. The vulnerability affects Apache
Santuario - XML Security for Java 2.0.x releases from 2.0.3 and all
2.1.x releases before 2.1.4.