A regression was found on RHEL-5.11 making apr-util and httpd vulnerable to billion laughs attack, also known as CVE-2009-1955, again.
Statement: Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.