{"id":"RLSA-2026:76763","summary":"Important: dovecot security, bug fix, and enhancement update","details":"Dovecot is an IMAP server for Linux and other UNIX-like systems, written primarily with security in mind. It also contains a small POP3 server, and supports e-mail in either the maildir or mbox format. The SQL drivers and authentication plug-ins are provided as subpackages. \n\nSecurity Fix(es):\n\n* dovecot: Dovecot: Denial of Service via IMAP ID command with excessive parameters (CVE-2026-42391)\n\n* dovecot: Dovecot: Authentication bypass via incorrect OAuth2 token validation (CVE-2026-73208)\n\n* dovecot: Dovecot: Denial of service via crafted email headers (CVE-2026-27852)\n\n* dovecot: Dovecot: Denial of Service via truncated quoted argument in ManageSieve (CVE-2026-40019)\n\n* dovecot: Dovecot: Denial of Service and potential message duplication via connection limit exhaustion (CVE-2026-33263)\n\n* dovecot: Dovecot: Denial of Service in ManageSieve login process (CVE-2026-33605)\n\n* dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free (CVE-2026-42007)\n\n* dovecot: Dovecot: MySQL multi-byte escaping wrong (CVE-2026-40018)\n\nBug Fix(es) and Enhancement(s):\n\n* Dovecot crashes when accessing mailbox with: \"Panic: file mail-user.c: line 229 (mail_user_deinit): assertion failed: ((*user)-\u003erefcount == 1)\" (JIRA:Rocky Linux-176273)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.","modified":"2026-10-07T06:30:02.504205974Z","published":"2026-10-07T06:01:37.070463Z","upstream":["CVE-2026-27852","CVE-2026-33263","CVE-2026-33605","CVE-2026-40018","CVE-2026-40019","CVE-2026-42007","CVE-2026-42391","CVE-2026-73208"],"database_specific":{"license_url":"https://creativecommons.org/licenses/by/4.0/","source_advisory":"RHSA-2026:76763","license":"CC-BY-4.0"},"references":[{"type":"ADVISORY","url":"https://errata.rockylinux.org/RLSA-2026:76763"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525545"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525547"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525557"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525559"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525567"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525576"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525583"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525584"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:76763"}],"affected":[{"package":{"name":"dovecot","ecosystem":"Rocky Linux:8","purl":"pkg:rpm/rocky-linux/dovecot?distro=rocky-linux-8&epoch=1"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.3.16-16.el8_10"}],"database_specific":{"yum_repository":"AppStream"}}],"database_specific":{"source":"https://storage.googleapis.com/resf-osv-data/RLSA-2026:76763.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H"}],"credits":[{"name":"Rocky Enterprise Software Foundation"},{"name":"Red Hat"}]}