{"id":"UBUNTU-CVE-2026-33605","details":"An unauthenticated attacker can crash the ManageSieve login process by sending a small malformed command before authenticating. If running in high-security mode (default for community releases), only the attacker's own connection is terminated. If running in high-performance mode (default for Pro releases), all connections handled by the same managesieve-login process are terminated. Repeating the attack can cause denial of service for Sieve script management. Restrict network access to the ManageSieve service to trusted clients. Update to non-vulnerable version. No publicly available exploits are known.","modified":"2026-09-02T19:36:12.994841844Z","published":"2026-08-28T00:00:00Z","upstream":["CVE-2026-33605"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33605"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33605"}],"affected":[{"package":{"name":"dovecot","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/dovecot?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:2.1.7-7ubuntu3","1:2.2.9-1ubuntu1","1:2.2.9-1ubuntu2","1:2.2.9-1ubuntu2.1","1:2.2.9-1ubuntu2.3","1:2.2.9-1ubuntu2.4","1:2.2.9-1ubuntu2.5","1:2.2.9-1ubuntu2.6","1:2.2.9-1ubuntu2.6+esm1","1:2.2.9-1ubuntu2.6+esm2","1:2.2.9-1ubuntu2.6+esm3","1:2.2.9-1ubuntu2.6+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"dovecot-core","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_version":"1:2.2.9-1ubuntu2.6+esm4","binary_name":"dovecot-gssapi"},{"binary_name":"dovecot-imapd","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_name":"dovecot-ldap","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_name":"dovecot-lmtpd","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_version":"1:2.2.9-1ubuntu2.6+esm4","binary_name":"dovecot-managesieved"},{"binary_version":"1:2.2.9-1ubuntu2.6+esm4","binary_name":"dovecot-mysql"},{"binary_name":"dovecot-pgsql","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_name":"dovecot-pop3d","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_version":"1:2.2.9-1ubuntu2.6+esm4","binary_name":"dovecot-sieve"},{"binary_name":"dovecot-solr","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_name":"dovecot-sqlite","binary_version":"1:2.2.9-1ubuntu2.6+esm4"},{"binary_name":"mail-stack-delivery","binary_version":"1:2.2.9-1ubuntu2.6+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33605.json"}},{"package":{"name":"dovecot","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/dovecot?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:2.2.18-2ubuntu2","1:2.2.22-1ubuntu1","1:2.2.22-1ubuntu2","1:2.2.22-1ubuntu2.1","1:2.2.22-1ubuntu2.2","1:2.2.22-1ubuntu2.3","1:2.2.22-1ubuntu2.4","1:2.2.22-1ubuntu2.6","1:2.2.22-1ubuntu2.7","1:2.2.22-1ubuntu2.8","1:2.2.22-1ubuntu2.9","1:2.2.22-1ubuntu2.10","1:2.2.22-1ubuntu2.11","1:2.2.22-1ubuntu2.12","1:2.2.22-1ubuntu2.13","1:2.2.22-1ubuntu2.14"],"ecosystem_specific":{"binaries":[{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-core"},{"binary_name":"dovecot-gssapi","binary_version":"1:2.2.22-1ubuntu2.14"},{"binary_name":"dovecot-imapd","binary_version":"1:2.2.22-1ubuntu2.14"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-ldap"},{"binary_name":"dovecot-lmtpd","binary_version":"1:2.2.22-1ubuntu2.14"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-lucene"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-managesieved"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-mysql"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-pgsql"},{"binary_name":"dovecot-pop3d","binary_version":"1:2.2.22-1ubuntu2.14"},{"binary_name":"dovecot-sieve","binary_version":"1:2.2.22-1ubuntu2.14"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-solr"},{"binary_version":"1:2.2.22-1ubuntu2.14","binary_name":"dovecot-sqlite"},{"binary_name":"mail-stack-delivery","binary_version":"1:2.2.22-1ubuntu2.14"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33605.json"}},{"package":{"name":"dovecot","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/dovecot?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:2.2.27-3ubuntu1","1:2.2.33.2-1ubuntu1","1:2.2.33.2-1ubuntu2","1:2.2.33.2-1ubuntu3","1:2.2.33.2-1ubuntu4","1:2.2.33.2-1ubuntu4.1","1:2.2.33.2-1ubuntu4.2","1:2.2.33.2-1ubuntu4.3","1:2.2.33.2-1ubuntu4.4","1:2.2.33.2-1ubuntu4.5","1:2.2.33.2-1ubuntu4.6","1:2.2.33.2-1ubuntu4.7","1:2.2.33.2-1ubuntu4.8"],"ecosystem_specific":{"binaries":[{"binary_version":"1:2.2.33.2-1ubuntu4.8","binary_name":"dovecot-core"},{"binary_name":"dovecot-gssapi","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_version":"1:2.2.33.2-1ubuntu4.8","binary_name":"dovecot-imapd"},{"binary_name":"dovecot-ldap","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_version":"1:2.2.33.2-1ubuntu4.8","binary_name":"dovecot-lmtpd"},{"binary_version":"1:2.2.33.2-1ubuntu4.8","binary_name":"dovecot-managesieved"},{"binary_name":"dovecot-mysql","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_name":"dovecot-pgsql","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_name":"dovecot-pop3d","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_name":"dovecot-sieve","binary_version":"1:2.2.33.2-1ubuntu4.8"},{"binary_version":"1:2.2.33.2-1ubuntu4.8","binary_name":"dovecot-so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