{"id":"USN-8253-2","summary":"postfix vulnerability","details":"USN-8253-1 fixed a vulnerability in Postfix. This update provides the\ncorresponding fix for Postfix on Ubuntu 14.04 LTS, Ubuntu 16.04 LTS,\nUbuntu 18.04 LTS, and Ubuntu 20.04 LTS.\n\nOriginal advisory details:\n\n Kamil Frankowicz discovered that Postfix incorrectly handled certain\n enhanced status codes. A remote attacker could possibly use this issue to\n cause Postfix to crash, resulting in a denial of service.","modified":"2026-06-10T01:29:28.789452016Z","published":"2026-06-03T20:22:56Z","related":["UBUNTU-CVE-2026-43964"],"upstream":["UBUNTU-CVE-2026-43964"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8253-2"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-43964"}],"affected":[{"package":{"name":"postfix","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/postfix?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11.0-1ubuntu1.2+esm4"}]}],"versions":["2.10.2-1","2.10.2-1build1","2.11.0-1","2.11.0-1ubuntu1","2.11.0-1ubuntu1.2","2.11.0-1ubuntu1.2+esm2","2.11.0-1ubuntu1.2+esm3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro","binaries":[{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix"},{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix-cdb"},{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix-ldap"},{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix-mysql"},{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix-pcre"},{"binary_version":"2.11.0-1ubuntu1.2+esm4","binary_name":"postfix-pgsql"}]},"database_specific":{"cves_map":{"cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/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"}],"id":"CVE-2026-43964"}],"ecosystem":"Ubuntu:Pro:14.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8253-2.json"}},{"package":{"name":"postfix","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/postfix?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.0-3ubuntu0.4+esm4"}]}],"versions":["2.11.3-1ubuntu2","2.11.3-1ubuntu3","3.0.4-1ubuntu1","3.0.4-2","3.0.4-3","3.0.4-5","3.0.4-5build1","3.1.0-3","3.1.0-3ubuntu0.1","3.1.0-3ubuntu0.2","3.1.0-3ubuntu0.3","3.1.0-3ubuntu0.4","3.1.0-3ubuntu0.4+esm2","3.1.0-3ubuntu0.4+esm3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro","binaries":[{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix"},{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix-cdb"},{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix-ldap"},{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix-mysql"},{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix-pcre"},{"binary_version":"3.1.0-3ubuntu0.4+esm4","binary_name":"postfix-pgsql"}]},"database_specific":{"cves_map":{"cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/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"}],"id":"CVE-2026-43964"}],"ecosystem":"Ubuntu:Pro:16.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8253-2.json"}},{"package":{"name":"postfix","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/postfix?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0-1ubuntu0.4+esm4"}]}],"versions":["3.2.3-1","3.2.3-1build1","3.2.4-1","3.2.5-1","3.2.5-1build1","3.3.0-1","3.3.0-1ubuntu0.1","3.3.0-1ubuntu0.2","3.3.0-1ubuntu0.3","3.3.0-1ubuntu0.4","3.3.0-1ubuntu0.4+esm2","3.3.0-1ubuntu0.4+esm3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-cdb"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-ldap"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-lmdb"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-mysql"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-pcre"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-pgsql"},{"binary_version":"3.3.0-1ubuntu0.4+esm4","binary_name":"postfix-sqlite"}]},"database_specific":{"cves_map":{"cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/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"}],"id":"CVE-2026-43964"}],"ecosystem":"Ubuntu:Pro:18.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8253-2.json"}},{"package":{"name":"postfix","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/postfix?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.13-0ubuntu1.4+esm1"}]}],"versions":["3.4.5-1ubuntu1","3.4.7-1","3.4.7-2","3.4.8-1","3.4.9-1","3.4.10-1","3.4.10-1ubuntu1","3.4.13-0ubuntu1","3.4.13-0ubuntu1.1","3.4.13-0ubuntu1.2","3.4.13-0ubuntu1.3","3.4.13-0ubuntu1.4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-cdb"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-ldap"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-lmdb"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-mysql"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-pcre"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-pgsql"},{"binary_version":"3.4.13-0ubuntu1.4+esm1","binary_name":"postfix-sqlite"}]},"database_specific":{"cves_map":{"cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/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"}],"id":"CVE-2026-43964"}],"ecosystem":"Ubuntu:Pro:20.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8253-2.json"}}],"schema_version":"1.7.5"}