{
  "cveId": "CVE-2026-42391",
  "url": "https://patchblox.com/security/cve/CVE-2026-42391",
  "summary": "CVE-2026-42391 is fixed in 12 products on 1 platform, first by RHSA-2026:79371, released August 28, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "dovecot: An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, whi...",
  "description": "An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by the same process. This can cause degradation or denial of service for IMAP logins. Limit the number of connections handled by a single imap-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.",
  "published": "2026-08-28T10:12:27Z",
  "severity": "important",
  "cvss": 9.1,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H",
  "epss": 0.00449,
  "epssPercentile": 0.39269,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "1:2.3.19.1\u002Bdfsg1-2.1\u002Bdeb12u7",
      "fix": "DEBIAN-CVE-2026-42391",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-42391",
      "released": "2026-09-10T12:12:19Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1:2.4.1\u002Bdfsg1-6\u002Bdeb13u7",
      "fix": "DEBIAN-CVE-2026-42391",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-42391",
      "released": "2026-09-10T12:12:19Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "Debian 14",
      "fixedVersion": "1:2.4.5\u002Bdfsg1-1",
      "fix": "DEBIAN-CVE-2026-42391",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-42391",
      "released": "2026-09-10T12:12:19Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "RHEL 10",
      "fixedVersion": "2.3.21-19.el10_2.8",
      "fix": "RHSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-79371",
      "released": "2026-08-28T10:12:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "RHEL 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RHSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-76763",
      "released": "2026-10-06T21:56:59Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "RHEL 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RHSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-80825",
      "released": "2026-10-13T23:30:48Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "almalinux 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ALSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "almalinux 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ALSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "almalinux 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ALSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-80825",
      "released": "2026-11-07T00:40:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "ol 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ELSA-2026-79371",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "ol 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ELSA-2026-76763",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "ol 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ELSA-2026-80825",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-80825",
      "released": "2026-11-07T00:52:27Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "rocky 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "RLSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-79371",
      "released": "2026-11-07T00:39:51Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "rocky 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RLSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-76763",
      "released": "2026-10-07T06:01:37Z"
    },
    {
      "platform": "linux",
      "product": "dovecot",
      "release": "rocky 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RLSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-80825",
      "released": "2026-11-07T00:39:57Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "RHEL 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RHSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-76763",
      "released": "2026-10-06T21:56:59Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "RHEL 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RHSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-80825",
      "released": "2026-10-13T23:30:48Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "almalinux 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ALSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "almalinux 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ALSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "almalinux 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ALSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-80825",
      "released": "2026-11-07T00:40:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "ol 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ELSA-2026-79371",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "ol 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ELSA-2026-76763",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-devel",
      "release": "ol 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ELSA-2026-80825",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-80825",
      "released": "2026-11-07T00:52:27Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "RHEL 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RHSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-76763",
      "released": "2026-10-06T21:56:59Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "RHEL 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RHSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-80825",
      "released": "2026-10-13T23:30:48Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "almalinux 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ALSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "almalinux 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ALSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "almalinux 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ALSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-80825",
      "released": "2026-11-07T00:40:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "ol 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ELSA-2026-79371",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "ol 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ELSA-2026-76763",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql",
      "release": "ol 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ELSA-2026-80825",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-80825",
      "released": "2026-11-07T00:52:27Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-mysql-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "RHEL 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RHSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-76763",
      "released": "2026-10-06T21:56:59Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "RHEL 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RHSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-80825",
      "released": "2026-10-13T23:30:48Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "almalinux 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ALSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "almalinux 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ALSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "almalinux 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ALSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-80825",
      "released": "2026-11-07T00:40:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "ol 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ELSA-2026-79371",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "ol 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ELSA-2026-76763",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql",
      "release": "ol 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ELSA-2026-80825",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-80825",
      "released": "2026-11-07T00:52:27Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pgsql-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "RHEL 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "RHSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-76763",
      "released": "2026-10-06T21:56:59Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "RHEL 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "RHSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-80825",
      "released": "2026-10-13T23:30:48Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "almalinux 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ALSA-2026:79371",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "almalinux 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ALSA-2026:76763",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "almalinux 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ALSA-2026:80825",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-80825",
      "released": "2026-11-07T00:40:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "ol 10",
      "fixedVersion": "1:2.3.21-19.el10_2.8",
      "fix": "ELSA-2026-79371",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-79371",
      "released": "2026-10-08T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "ol 8",
      "fixedVersion": "1:2.3.16-16.el8_10",
      "fix": "ELSA-2026-76763",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-76763",
      "released": "2026-10-06T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole",
      "release": "ol 9",
      "fixedVersion": "1:2.3.16-18.el9_8.8",
      "fix": "ELSA-2026-80825",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-80825",
      "released": "2026-11-07T00:52:27Z"
    },
    {
      "platform": "linux",
      "product": "dovecot-pigeonhole-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:2.3.20-1.amzn2023.0.4",
      "fix": "ALAS2023-2026-3109",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3109",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "dovecot23",
      "release": "sles 15.6",
      "fixedVersion": "2.3.21.1-150200.76.1",
      "fix": "SUSE-SU-2026:4139-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4139-1",
      "released": "2026-09-14T07:22:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot23",
      "release": "sles 15.7",
      "fixedVersion": "2.3.21.1-150200.76.1",
      "fix": "SUSE-SU-2026:4139-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4139-1",
      "released": "2026-09-14T07:22:32Z"
    },
    {
      "platform": "linux",
      "product": "dovecot24",
      "release": "opensuse-leap 16.0",
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      "fix": "OPENSUSE-SU-2026:21720-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21720-1",
      "released": "2026-09-01T14:18:02Z"
    },
    {
      "platform": "linux",
      "product": "dovecot24",
      "release": "sles 16.0",
      "fixedVersion": "2.4.4-160000.2.1",
      "fix": "SUSE-SU-2026:23595-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23595-1",
      "released": "2026-09-01T14:12:16Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}