CVE-2026-107576

{
  "etk_id": "ETK-2026-1280",
  "cve_id": "CVE-2026-107576",
  "display_id": "CVE-2026-107576",
  "ghsa_id": "GHSA-6pj8-9c42-v5rp",
  "euvd_id": "EUVD-2026-94859",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Algorithmic complexity DoS in hMailServer DKIM and ARC verification",
  "summary": "hMailServer 6.0.0 through 6.3.5 can spend excessive time processing inbound DKIM and ARC signatures. An unauthenticated remote sender can tie up mail-processing workers and disrupt SMTP or message delivery when inbound signature verification handles a signed message under the sender's control.",
  "mitigation": "Upgrade hMailServer to version 6.3.6. Until the upgrade is complete, reduce exposure by limiting or filtering untrusted inbound mail that reaches DKIM and ARC verification.",
  "vendor": "Progressive Robot Ltd",
  "product": "hMailServer",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 6.0.0, < 6.3.6"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "6.3.6"
      ],
      "package_name": "hMailServer",
      "purl": null
    }
  ],
  "cwes": [
    407
  ],
  "cvss_score": 7.5,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss_score": 0.0043,
  "epss_percentile": 0.357,
  "epss_asof": "2026-10-20",
  "automation": "deterministic",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 77.66707086666666,
  "t0_at": "2026-10-08T11:46:56.083000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-08T11:46:56.083000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-08T11:46:56.083000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-107576"
    }
  }
}