ETK-2026-2553Zero's internal tracking ID, independent of the CVE number.

{
  "etk_id": "ETK-2026-2553",
  "cve_id": null,
  "display_id": "ETK-2026-2553",
  "ghsa_id": "GHSA-8628-6j2f-ppm9",
  "euvd_id": null,
  "status": "published",
  "anchor_state": "awaiting_cve",
  "title": "Heap buffer overflow in h2o static-file compression handling",
  "summary": "h2o's compressed static-file variant handling can write past a heap buffer. A remote client advertising Zstd support can crash a worker when `file.send-compressed` is enabled.",
  "mitigation": "Upgrade h2o to commits a60aea4 and above or later.",
  "vendor": "other",
  "product": "other:h2o",
  "affected": [
    {
      "affected_notes": [
        "commits up to d21e7cb"
      ],
      "affected_ranges": [],
      "ecosystem": "other",
      "fixed_versions": [
        "commits a60aea4 and above"
      ],
      "package_name": "h2o",
      "purl": null
    }
  ],
  "cwes": null,
  "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": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "deterministic",
  "check": true,
  "check_confidence_basis": "differential",
  "exploit": false,
  "pipeline_minutes": 24.627988816666665,
  "t0_at": null,
  "signals": {
    "check": {
      "at": "2026-10-24T17:27:27.167798+00:00",
      "days": -0.22344157537037038,
      "is_lower_bound": true,
      "measured_at": "2026-10-24T22:49:12.579037+00:00",
      "url": null
    },
    "trigger_signal": {
      "at": "2026-10-23T08:58:54+00:00",
      "days": -1.5766032396990741,
      "is_lower_bound": true,
      "measured_at": "2026-10-24T22:49:12.579037+00:00",
      "url": "https://github.com/h2o/h2o/security/advisories/GHSA-8628-6j2f-ppm9"
    }
  }
}