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CVE-2026-72398

Estado: RecibidaCrítica (9.8)—

In the Linux kernel, the following vulnerability has been resolved:

sctp: add INIT verification after cookie unpacking

In SCTP handshake, the INIT chunk is initially processed by the server and embedded into the cookie carried in INIT-ACK. The client then returns this cookie via COOKIE-ECHO, where the server unpacks it and reconstructs the original INIT chunk.

When cookie authentication is enabled, the cookie contents are protected against tampering, so reusing the unpacked INIT without re-verification is safe.

However, when cookie authentication is disabled, the reconstructed INIT can no longer be trusted. In this case, the INIT must be explicitly validated after unpacking to avoid processing potentially tampered data.

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Add sctp_verify_init() checks after cookie unpacking in COOKIE-ECHO processing paths (sctp_sf_do_5_1D_ce() and sctp_sf_do_5_2_4_dupcook()) when cookie_auth_enable is disabled. On failure, the new association is freed and the packet is discarded.

Also tighten cookie validation in sctp_unpack_cookie() by verifying the embedded chunk type is SCTP_CID_INIT before treating it as an INIT chunk.

Finally, update sctp_verify_init() to validate parameter bounds using the actual embedded INIT length instead of chunk->chunk_end, since the INIT stored in COOKIE-ECHO may not span the entire chunk buffer.

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 SCTP del kernel Linux accesible remotamente sin autenticación (AV:N, PR:N, UI:N). Ejecución de código por procesamiento de paquetes SCTP malformados; potencial DoS por rechazo de servicio en el handshake.

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

Privileged Account ManagementFilter Network TrafficVulnerability ScanningRestrict Web-Based ContentNetwork SegmentationLimit Software Installation

Tecnologías afectadas (1)

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

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-72398",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "bca3100f550281c2f2418652338bced3b35af0e6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "062bcbf8d1f1051fdeb20b94920031b0e2cb95a2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "414c5447fe6a200613dd46d7fdc8454622076cb1",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/sctp/sm_make_chunk.c",
            "net/sctp/sm_statefuns.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.12",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/sctp/sm_make_chunk.c",
            "net/sctp/sm_statefuns.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:22:13.363",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/062bcbf8d1f1051fdeb20b94920031b0e2cb95a2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/414c5447fe6a200613dd46d7fdc8454622076cb1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bca3100f550281c2f2418652338bced3b35af0e6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: add INIT verification after cookie unpacking\n\nIn SCTP handshake, the INIT chunk is initially processed by the server\nand embedded into the cookie carried in INIT-ACK. The client then\nreturns this cookie via COOKIE-ECHO, where the server unpacks it and\nreconstructs the original INIT chunk.\n\nWhen cookie authentication is enabled, the cookie contents are protected\nagainst tampering, so reusing the unpacked INIT without re-verification\nis safe.\n\nHowever, when cookie authentication is disabled, the reconstructed INIT\ncan no longer be trusted. In this case, the INIT must be explicitly\nvalidated after unpacking to avoid processing potentially tampered data.\n\nAdd sctp_verify_init() checks after cookie unpacking in COOKIE-ECHO\nprocessing paths (sctp_sf_do_5_1D_ce() and sctp_sf_do_5_2_4_dupcook())\nwhen cookie_auth_enable is disabled. On failure, the new association is\nfreed and the packet is discarded.\n\nAlso tighten cookie validation in sctp_unpack_cookie() by verifying the\nembedded chunk type is SCTP_CID_INIT before treating it as an INIT\nchunk.\n\nFinally, update sctp_verify_init() to validate parameter bounds using\nthe actual embedded INIT length instead of chunk->chunk_end, since the\nINIT stored in COOKIE-ECHO may not span the entire chunk buffer."
    }
  ],
  "lastModified": "2026-08-17T06:19:06.373",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}