Cyrus IMAP is vulnerble to denial of service. It allows remote attackers to cause a denial of service (multiple-minute daemon hang) via input that is mishandled during hash-table interaction. Because there are many insertions into a single bucket, strcmp becomes slow.
cyrus.topicbox.com/groups/announce/T3dde0a2352462975-M1386fc44adf967e072f8df13/cyrus-imap-3-4-2-3-2-8-and-3-0-16-released
github.com/cyrusimap/cyrus-imapd/commits/master
github.com/cyrusimap/cyrus-imapd/security/advisories
lists.debian.org/debian-lts-announce/2022/06/msg00013.html
lists.fedoraproject.org/archives/list/[email protected]/message/6HEO3RURJW6NLIXS7NK5PVU6MGHC4SCM/
lists.fedoraproject.org/archives/list/[email protected]/message/WJZB45QBUN7CZFGOWCZYUYACNBTX7LVS/
security-tracker.debian.org/tracker/CVE-2021-33582
www.cyrusimap.org/imap/download/release-notes/index.html