Debian: DSA-4664-1: mailman security update
Summary
For the oldstable distribution (stretch), this problem has been fixed
in version 1:2.1.23-1+deb9u5.
For the stable distribution (buster), this problem has been fixed in
version 1:2.1.29-1+deb10u1.
We recommend that you upgrade your mailman packages.
For the detailed security status of mailman please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/mailman
Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/