{"id":"UBUNTU-CVE-2025-59028","details":"When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail. Invalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. Install fixed version or disable concurrency in login processes (heavy perfomance penalty on large deployments). No publicly available exploits are known.","modified":"2026-05-04T10:33:45.711180Z","published":"2026-03-27T00:00:00Z","related":["USN-8136-1"],"upstream":["CVE-2025-59028"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-59028"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-59028"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8136-1"}],"affected":[{"package":{"name":"dovecot","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/dovecot@1:2.4.1+dfsg1-5ubuntu4.1?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.4.1+dfsg1-5ubuntu4.1"}]}],"versions":["1:2.3.21.1+dfsg1-1ubuntu2","1:2.4.1+dfsg1-5ubuntu1","1:2.4.1+dfsg1-5ubuntu3","1:2.4.1+dfsg1-5ubuntu4"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"dovecot-auth-lua","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-core","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-flatcurve","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-gssapi","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-imapd","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-ldap","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_version":"1:2.4.1+dfsg1-5ubuntu4.1","binary_name":"dovecot-lmtpd"},{"binary_name":"dovecot-managesieved","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-mysql","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_version":"1:2.4.1+dfsg1-5ubuntu4.1","binary_name":"dovecot-pgsql"},{"binary_name":"dovecot-pop3d","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-sieve","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_name":"dovecot-solr","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"},{"binary_version":"1:2.4.1+dfsg1-5ubuntu4.1","binary_name":"dovecot-sqlite"},{"binary_name":"dovecot-submissiond","binary_version":"1:2.4.1+dfsg1-5ubuntu4.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59028.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}