In words.protocols.jabber.xmlstream in Twisted through 19.2.1, XMPP support did not verify certificates when used with TLS, allowing an attacker to MITM connections.
lists.opensuse.org/opensuse-security-announce/2019-09/msg00013.html
lists.opensuse.org/opensuse-security-announce/2019-09/msg00028.html
github.com/twisted/twisted/pull/1147
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PLTZDMFBNFSJMBXYJNGJHENJA4H2TSMZ/
twistedmatrix.com/trac/ticket/9561
usn.ubuntu.com/4308-1/
usn.ubuntu.com/4308-2/
www.oracle.com/security-alerts/cpuapr2020.html