In libxml2 before 2.9.14 several buffer handling functions in buf.c (xmlBuf*) and tree.c (xmlBuffer*) don't check for integer overflows. This can result in out-of-bounds memory writes. Exploitation requires a victim to open a crafted multi-gigabyte XML file. Other software using libxml2's buffer functions for example libxslt through 1.1.35 is affected as well.