{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "5.9.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "922d04b3568c6428a9fb905ddee3ef5a68db3108"
            }
          ],
          "repo": "https://github.com/wolfssl/wolfssl",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "wolfSSL",
    "cwe_ids": [
      "CWE-122"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3549.json"
  },
  "details": "Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.",
  "id": "CVE-2026-3549",
  "modified": "2026-07-16T03:30:59.153846800Z",
  "published": "2026-03-19T20:09:27.036Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3549.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3549"
    },
    {
      "type": "FIX",
      "url": "https://github.com/wolfSSL/wolfssl/pull/9817"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ECH parsing heap buffer overflow"
}