Important: dovecot security update

{
  "id": "8f83bd66c7a1bf14ad259f057c4f23ec5f9f2627858b8d94ce314a358f93b3ee",
  "url": "https://osv.dev/vulnerability/RLSA-2026%3A79371",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Important: dovecot security update",
    "summary": "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. Security Fix(es): * dovecot: Dovecot: Denial of Service via IMAP ID command with excessive parameters (CVE-2026-42391) * dovecot: Dovecot: Authentication bypass via incorrect OAuth2 token validation (CVE-2026-73208) * dovecot: Dovecot: Denial of service via crafted email headers (CVE-2026-27852) * dovecot: Dovecot: Denial of Service via truncated quoted argument in ManageSieve (CVE-2026-40019) * dovecot: Dovecot: Denial of Service and potential message duplication via connection limit exhaustion (CVE-2026-33263) * dovecot: Dovecot: Denial of Service in ManageSieve login process (CVE-2026-33605) * dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free (CVE-2026-42007) * dovecot: Dovecot: MySQL multi-byte escaping wrong (CVE-2026-40018) For 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.",
    "evidence": "osv:RLSA-2026:79371",
    "products": [
      {
        "name": {
          "value": "dovecot",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:2.3.21-19.el10_2.8",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "RLSA-2026:79371",
      "aliases": [
        "RLSA-2026:79371"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:2.3.21-19.el10_2.8"
                }
              ],
              "database_specific": {
                "yum_repository": "AppStream"
              }
            }
          ],
          "package": {
            "name": "dovecot",
            "purl": "pkg:rpm/rocky-linux/dovecot?distro=rocky-linux-10&epoch=1",
            "ecosystem": "Rocky Linux:10"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/resf-osv-data/RLSA-2026:79371.json"
          }
        }
      ],
      "modified": "2026-10-10T12:30:02.802466374Z",
      "provider": "osv",
      "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"
      ],
      "references": [
        "https://errata.rockylinux.org/RLSA-2026:79371",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525545",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525547",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525557",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525559",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525567",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525576",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525583",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2525584",
        "https://access.redhat.com/errata/RHSA-2026:79371"
      ],
      "provider_metadata": {
        "license": "CC-BY-4.0",
        "license_url": "https://creativecommons.org/licenses/by/4.0/",
        "source_advisory": "RHSA-2026:79371"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-27852",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-33263",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-33605",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-40018",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-40019",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-42007",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-42391",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-73208",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 249467,
  "published_at": "2026-10-10T12:08:29.652489+00:00"
}