Dovecot regression

Summary

USN-8136-1 fixed vulnerabilities in Dovecot. The update caused a regression on Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that Dovecot incorrectly handled invalid base64 SASL data. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-59028) It was discovered that Dovecot script decode2text.sh incorrectly handled zip files. An attacker could possibly use this issue to obtain sensitive information. (CVE-2025-59031) It was discovered that Dovecot incorrectly handled certain AUTHENTICATE requests. An attacker could possibly use this issue to cause a denial of service. (CVE-2025-59032) It was discovered that Dovecot incorrectly handled certain SQL based authentication. An attacker could possibly use this issue to bypass authentication. This issue only affected Ubuntu 25.10. (CVE-2026-24031) It was discovered that Dovecot incorrectly handled certain LDAP based authentication. An attacker could possibly use this issue to bypass restrictions and allow probing of LDAP structure. This issue only affected Ubuntu 25.10. (CVE-2026-27860) It was discovered that Dovecot is vulnerable to replay attack under certain conditions. An attacker could possibly use this issue to bypass authentication. (CVE-2026-27855) It was dis Affected Ubuntu releases: 24.04, 22.04. CVEs: CVE-2026-0394.