{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "6.2.28"
              },
              {
                "fixed": "6.3.6"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "f088336c208817816c87c88c0ede7bb079c2a6ab"
            },
            {
              "fixed": "e3c448aa66fc310b74d076884d54fae951296915"
            }
          ],
          "repo": "https://gitlab.com/hmailserver/hmailserver",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "GitLab",
    "cwe_ids": [
      "CWE-407"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107574.json"
  },
  "details": "Inefficient algorithmic complexity in the JSON reader of Progressive Robot hMailServer allows a remote unauthenticated attacker to make the mail services unavailable. Reading a JSON object kept the first of each duplicated member name by searching the members already read, so an object of N distinct member names cost O(N^2): 1 MB took 8.9 seconds and 4 MB took 300 seconds against the affected code. A remote attacker reaches the reader without an account by mailing a crafted TLS-RPT report (up to 16 MB after decompression) to a hosted domain's published report mailbox, which is read on a delivery thread; a few such reports hold every delivery thread (ten by default), so the server delivers no mail, local or outbound, for over an hour per report. A signed-in account reaches the same 16 MB body through the webmail's own REST routes, holding the REST API's own worker threads. Where no report mailbox is configured, the unauthenticated REST sign-in routes that read a JSON body are capped at 64 KB and are not affected.",
  "id": "CVE-2026-107574",
  "modified": "2026-10-10T02:30:57.507792676Z",
  "published": "2026-10-08T11:46:26.206Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/hmailserver/hmailserver/-/work_items/76"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107574.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107574"
    },
    {
      "type": "PACKAGE",
      "url": "https://gitlab.com/hmailserver/hmailserver"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Inefficient Algorithmic Complexity in hMailServer"
}