Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:9 relevant versions.
A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixed content, causing a NULL dereference. If an untrusted XML document was parsed in recovery mode and post-validated, the flaw could be used to crash the application. The highest threat from this vulnerability is to system availability.
libxml2 to version 2.9.4+dfsg1-2.2+deb9u4 or higher.