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CVE-2026-75806

Estado: En análisisMedia (5.3)—

Issue summary: An established DTLS 1.2 association using an AEAD cipher suite can be terminated by a single unauthenticated datagram whose encrypted fragment is shorter than the mandatory explicit IV and authentication tag overhead.

Impact summary: An attacker who can send a datagram that is routed to an existing DTLS 1.2 association can tear that association down without knowing any key material. This is a Denial of Service limited to the targeted association. There is no memory safety or confidentiality impact.

CWE: CWE-1284: Improper Validation of Specified Quantity in Input

Description: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher suite carries an explicit IV followed by the ciphertext and an authentication tag.

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When decrypting such a record the record layer passed the record length to the cipher implementation before checking that the record was long enough to contain the explicit IV and the tag. For a record shorter than that overhead the cipher implementation rejected the impossible length, and the record layer treated this as an internal failure and raised a fatal internal_error alert instead of treating the record as one that failed authentication.

In TLS 1.2 the same record causes a fatal internal_error alert instead of the expected bad_record_mac alert. Since any undecryptable record already terminates a TLS connection, this is a protocol conformance issue rather than a security issue in TLS.

The fix validates the record length against the explicit IV and tag length before any AEAD processing, so that TLS reports bad_record_mac and DTLS silently discards the record.

FIPS impact: no The affected code is outside the FIPS module boundary.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad en validación de registros DTLS 1.2 (CWE-1284) explotable remotamente sin autenticación (AV:N/PR:N) para desconectar asociaciones existentes (DoS). No requiere interacción del usuario.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Openssl — OpensslAI

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-75806",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-75806",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-29T16:52:47.298458Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "openssl-security@openssl.org",
      "affectedData": [
        {
          "vendor": "OpenSSL",
          "product": "OpenSSL",
          "versions": [
            {
              "status": "affected",
              "version": "4.0.0",
              "lessThan": "4.0.3",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "3.6.0",
              "lessThan": "3.6.5",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "3.5.0",
              "lessThan": "3.5.9",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "3.4.0",
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            {
              "status": "affected",
              "version": "3.0.0",
              "lessThan": "3.0.23",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "1.1.1",
              "lessThan": "1.1.1zj",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-09-29T16:17:11.217",
  "references": [
    {
      "url": "https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d",
      "source": "openssl-security@openssl.org"
    },
    {
      "url": "https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972",
      "source": "openssl-security@openssl.org"
    },
    {
      "url": "https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d",
      "source": "openssl-security@openssl.org"
    },
    {
      "url": "https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d",
      "source": "openssl-security@openssl.org"
    },
    {
      "url": "https://openssl-library.org/news/secadv/20260929.txt",
      "source": "openssl-security@openssl.org"
    }
  ],
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "openssl-security@openssl.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-1284"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary."
    }
  ],
  "lastModified": "2026-09-29T21:27:41.130",
  "sourceIdentifier": "openssl-security@openssl.org"
}