mailman is vulnerable to content injection. An attacker is able to inject arbitrary content in GNU Mailman.
lists.opensuse.org/opensuse-security-announce/2020-05/msg00036.html
lists.opensuse.org/opensuse-security-announce/2020-06/msg00003.html
lists.opensuse.org/opensuse-security-announce/2020-10/msg00047.html
lists.opensuse.org/opensuse-security-announce/2020-10/msg00063.html
bugs.launchpad.net/mailman/+bug/1873722
code.launchpad.net/mailman
lists.debian.org/debian-lts-announce/2020/05/msg00007.html
lists.debian.org/debian-lts-announce/2020/07/msg00007.html
lists.fedoraproject.org/archives/list/[email protected]/message/74EQIVFB34Q4UYAQLCUWG55YLKAUWCHD/
mail.python.org/pipermail/mailman-announce/
security-tracker.debian.org/tracker/CVE-2020-12108
usn.ubuntu.com/4354-1/
www.debian.org/security/2021/dsa-4991