The cyrus-imapd packages contain a high-performance mail server with IMAP, POP3, NNTP, and Sieve support. Multiple buffer overflow flaws were found in the Cyrus IMAP Sieve implementation. An authenticated user able to create Sieve mail filtering rules could use these flaws to execute arbitrary code with the privileges of the Cyrus IMAP server user. Users of cyrus-imapd are advised to upgrade to these updated packages, which contain backported patches to resolve these issues. After installing the update, cyrus-imapd will be restarted automatically.