The OpenSSL Library now supports Encrypted Client Hello (ECH)

{
  "id": "4efb34b04d51477aa80c7eb652879143ec88be43ff34cbf4bbbd9a6fe561499e",
  "url": "https://openssl-library.org/post/2026-03-11-ech/",
  "method": "llm",
  "payload": {
    "kind": "other",
    "title": "The OpenSSL Library now supports Encrypted Client Hello (ECH)",
    "summary": "OpenSSL now supports ECH shared-mode, enabling applications to encrypt most of the TLS 1.3 ClientHello. ECH split-mode is not implemented.",
    "evidence": "The OpenSSL Library now supports Encrypted Client Hello (ECH) specified in RFC 9849",
    "products": [
      {
        "name": {
          "value": "OpenSSL Library",
          "evidence": "The OpenSSL Library now supports Encrypted Client Hello (ECH)"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "fixed_cves": [],
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "official-openssl-news",
  "document_id": 24085,
  "published_at": "2026-03-11T00:00:00+00:00"
}