{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f05aeb8322e2f61096af6b089d61ba6f40587d96"
            }
          ],
          "repo": "https://github.com/mailu/mailu",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-crww-m82r-2wfm"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-285",
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86009.json"
  },
  "details": "Mailu is a mail server distributed as a set of Docker images. Prior to f05aeb8322e2f61096af6b089d61ba6f40587d96, domain managers can enable spoofing for hosted domains they do not control. A potentially malicious domain administrator enables spoofing for another hosted domain and can send emails that are authenticated with DKIM/SPF for domains they should not be able to. This vulnerability is addressed by f05aeb8322e2f61096af6b089d61ba6f40587d96.",
  "id": "CVE-2026-86009",
  "modified": "2026-10-17T02:30:28.655155857Z",
  "published": "2026-10-16T16:19:06.420Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86009.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/Mailu/Mailu/issues/2686"
    },
    {
      "type": "FIX",
      "url": "https://github.com/Mailu/Mailu/pull/4072"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86009"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Mailu: Domain managers can allow themselves to spoof on other hosted domains they should not control"
}