This security update resolves two privately reported vulnerabilities in the
Pragmatic General Multicast (PGM) protocol that could allow a denial of service
if malformed PGM packets are received by an affected system. An attacker who
successfully exploited this vulnerability could cause a user’s system to become
non-responsive and to require a restart to restore functionality. Note that the
denial of service vulnerability would not allow an attacker to execute code or
to elevate their user rights, but it could cause the affected system to stop
accepting requests.