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CVE-2026-89969

Estado: RecibidaCrítica (9.8)—

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

nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU

nvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte queue->pdu union, then computes the remaining payload length as

and reads that many more bytes into &queue->pdu + queue->offset, without ever bounding the result against sizeof(queue->pdu).

A struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the union. Once a header digest has been negotiated (hdgst = 4), a second ICReq passes the hlen == nvmet_tcp_pdu_size() check but yields queue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the 128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and queue->data_digest. Those bytes are attacker-controlled (an ICReq carries no digest), and the duplicate ICReq is only rejected later, after the overflow. A remote unauthenticated host can thus corrupt kernel memory adjacent to the receive buffer.

Leer descripción completaMostrar menos

Reject any PDU whose declared length would read past the end of queue->pdu before the second recv.

Detalles técnicos trazas, registros y código del informe original
	queue->left = hdr->hlen - queue->offset + hdgst;

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 nvmet-tcp (servicio de red TCP del kernel Linux) explotable remotamente sin autenticación (AV:N/PR:N/UI:N). El overflow de buffer permite corrupción de memoria del kernel adyacente, causando DoS o manipulación de datos del sistema.

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.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-89969",
  "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": [
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              "status": "affected",
              "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30",
              "lessThan": "a3f0bcfbaf3312a5754d1ce020a07d394669eb25",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30",
              "lessThan": "4f84d42c53c49557fb1ef285c683b0a81b576c74",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30",
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              "versionType": "git"
            },
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              "lessThan": "cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca",
              "versionType": "git"
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            {
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              "lessThan": "3a385e0c39efbe34db8edd95900c123113ae3450",
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            },
            {
              "status": "affected",
              "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30",
              "lessThan": "dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6",
              "versionType": "git"
            },
            {
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            {
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              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/nvme/target/tcp.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/nvme/target/tcp.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-16T11:17:07.527",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/14cc5a7e77731497d5bea70f3bb05df7eda982e4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3a385e0c39efbe34db8edd95900c123113ae3450",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4f84d42c53c49557fb1ef285c683b0a81b576c74",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a3f0bcfbaf3312a5754d1ce020a07d394669eb25",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d95d342bc0ea82dc79e6362b2f1f997431750e4c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: fix out-of-bounds write when receiving an over-long PDU\n\nnvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte\nqueue->pdu union, then computes the remaining payload length as\n\n\tqueue->left = hdr->hlen - queue->offset + hdgst;\n\nand reads that many more bytes into &queue->pdu + queue->offset, without\never bounding the result against sizeof(queue->pdu).\n\nA struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the\nunion. Once a header digest has been negotiated (hdgst = 4), a second\nICReq passes the hlen == nvmet_tcp_pdu_size() check but yields\nqueue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the\n128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and\nqueue->data_digest. Those bytes are attacker-controlled (an ICReq\ncarries no digest), and the duplicate ICReq is only rejected later,\nafter the overflow. A remote unauthenticated host can thus corrupt\nkernel memory adjacent to the receive buffer.\n\nReject any PDU whose declared length would read past the end of\nqueue->pdu before the second recv."
    }
  ],
  "lastModified": "2026-09-16T15:18:21.240",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}