CVE-2026-56862

{
  "id": "CVE-2026-56862",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-13T22:17:22.550",
  "lastModified": "2026-10-24T16:10:00.153",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely."
    },
    {
      "lang": "es",
      "value": "Los mensajes de handshake, como KeyUpdate, siempre se consideran que avanzan el estado, independientemente de si un handshake se ha completado o no. Como resultado, un cliente malicioso puede seguir enviando mensajes KeyUpdate para forzar al servidor a seguir realizando operaciones de derivación de claves indefinidamente."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Go standard library",
          "product": "crypto/tls",
          "defaultStatus": "unaffected",
          "collectionURL": "https://pkg.go.dev",
          "packageName": "crypto/tls",
          "programRoutines": [
            {
              "name": "Conn.readRecordOrCCS"
            },
            {
              "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.Start"
            }
          ],
          "versions": [
            {
              "version": "0",
              "lessThan": "1.25.13",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "1.26.0-0",
              "lessThan": "1.26.6",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "1.27.0-0",
              "lessThan": "1.27.0-rc.3",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-14T15:27:34.651997Z",
          "id": "CVE-2026-56862",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://go.dev/cl/804261",
      "source": "[email protected]"
    },
    {
      "url": "https://go.dev/issue/80528",
      "source": "[email protected]"
    },
    {
      "url": "https://groups.google.com/g/golang-announce/c/94pEornpRlI",
      "source": "[email protected]"
    },
    {
      "url": "https://pkg.go.dev/vuln/GO-2026-6090",
      "source": "[email protected]"
    }
  ]
}