data/cve/v5/GO-2026-5856.json

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.0",
  "cveMetadata": {
    "cveId": "CVE-2026-42505"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc"
      },
      "title": "Invoking Encrypted Client Hello privacy leak in crypto/tls",
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "affected": [
        {
          "vendor": "Go standard library",
          "product": "crypto/tls",
          "collectionURL": "https://pkg.go.dev",
          "packageName": "crypto/tls",
          "versions": [
            {
              "version": "0",
              "lessThan": "1.25.12",
              "status": "affected",
              "versionType": "semver"
            },
            {
              "version": "1.26.0-0",
              "lessThan": "1.26.5",
              "status": "affected",
              "versionType": "semver"
            },
            {
              "version": "1.27.0-0",
              "lessThan": "1.27.0-rc.2",
              "status": "affected",
              "versionType": "semver"
            }
          ],
          "programRoutines": [
            {
              "name": "clientHelloMsg.marshalMsg"
            },
            {
              "name": "Conn.Handshake"
            },
            {
              "name": "Conn.HandshakeContext"
            },
            {
              "name": "Conn.Read"
            },
            {
              "name": "Conn.Write"
            },
            {
              "name": "Dial"
            },
            {
              "name": "DialWithDialer"
            },
            {
              "name": "Dialer.Dial"
            },
            {
              "name": "Dialer.DialContext"
            },
            {
              "name": "QUICConn.HandleData"
            },
            {
              "name": "QUICConn.SendSessionTicket"
            },
            {
              "name": "QUICConn.Start"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-201: Insertion of Sensitive Information Into Sent Data"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://go.dev/cl/775960"
        },
        {
          "url": "https://go.dev/issue/79282"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5856"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Coia Prant (github.com/rbqvq)"
        }
      ]
    }
  }
}