{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": [
              "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*",
              "cpe:2.3:a:golang:go:1.27:rc1:*:*:*:*:*:*"
            ],
            "extracted_events": [
              {
                "introduced": "1.23.0"
              },
              {
                "fixed": "1.25.12"
              },
              {
                "introduced": "1.26.0"
              },
              {
                "fixed": "1.26.5"
              },
              {
                "introduced": "1.27-rc1"
              },
              {
                "last_affected": "1.27-rc1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "CPE_STRING"
            ]
          },
          "events": [
            {
              "introduced": "6885bad7dd86880be6929c02085e5c7a67ff2887"
            },
            {
              "fixed": "d80d9a98f7e3a8f9b3a82d2c6079f84eb1101d46"
            },
            {
              "introduced": "d90b98e65320778f3b1f99a6951ab20f04d218b3"
            },
            {
              "fixed": "c19862e5f8415b4f24b189d065ed739517c548ba"
            },
            {
              "introduced": "eefb454307250192f45fa3718685e4c0a90e281d"
            },
            {
              "last_affected": "eefb454307250192f45fa3718685e4c0a90e281d"
            }
          ],
          "repo": "https://github.com/golang/go",
          "type": "GIT"
        }
      ],
      "versions": [
        "1.27-rc1"
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Go",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42505.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "fixed": "1.25.12"
          },
          {
            "introduced": "1.26.0-0"
          },
          {
            "fixed": "1.26.5"
          },
          {
            "introduced": "1.27.0-0"
          },
          {
            "fixed": "1.27.0-rc.2"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.",
  "id": "CVE-2026-42505",
  "modified": "2026-09-18T03:30:21.780963613Z",
  "published": "2026-07-08T15:46:33.407Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://go.dev/cl/775960"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/issue/79282"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-5856"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42505.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42505"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Invoking Encrypted Client Hello privacy leak in crypto/tls"
}