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CVE-2026-74695

Estado: RecibidaAlta (7.5)—

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

netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()

Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dst_entry assigned during earlier RX or routing steps.

Calling skb_dst_set_noref() when skb already holds a ref-counted dst overwrites skb->_skb_refdst, leaking the previous dst_entry reference count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in skb_dst_check_unset():

Drop any existing dst_entry reference with skb_dst_drop(skb) before setting the non-referenced flowtable destination.

Detalles técnicos trazas, registros y código del informe original
  WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170
  WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234
  WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864

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 de DoS en kernel Linux (AV:N, A:H) explotable remotamente sin autenticación. La fuga de referencias causa degradación de rendimiento/crash.

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)

Mostrar
{
  "id": "CVE-2026-74695",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "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": "2a79fd3908acd88e6cb0e620c314d7b1fee56a02",
              "lessThan": "12afa450a6a6c0cce2c42b7545a9958f62d8a00c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2a79fd3908acd88e6cb0e620c314d7b1fee56a02",
              "lessThan": "538e67e8c7889cf5f93951f5309d1bcb41f86036",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2a79fd3908acd88e6cb0e620c314d7b1fee56a02",
              "lessThan": "8aecf0bbcc72605592134c917c222207d8f63ab0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b4b1adf2e66ecc7125c4117e7aad9ff61e2cfd27",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "209dedf806d31095968f54323dbe62525b077b33",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4.16.15",
              "lessThan": "4.17",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "4.17.1",
              "lessThan": "4.18",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "net/netfilter/nf_flow_table_ip.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.18"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.18",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/netfilter/nf_flow_table_ip.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:44.050",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/12afa450a6a6c0cce2c42b7545a9958f62d8a00c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/538e67e8c7889cf5f93951f5309d1bcb41f86036",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8aecf0bbcc72605592134c917c222207d8f63ab0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()\n\nIncoming skbs passing through netfilter flowtable offload hooks (or XFRM\noffload path) might already carry a ref-counted dst_entry assigned during\nearlier RX or routing steps.\n\nCalling skb_dst_set_noref() when skb already holds a ref-counted dst\noverwrites skb->_skb_refdst, leaking the previous dst_entry reference\ncount and triggering a DEBUG_NET_WARN_ON_ONCE assertion in\nskb_dst_check_unset():\n\n  WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170\n  WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234\n  WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864\n\nDrop any existing dst_entry reference with skb_dst_drop(skb) before\nsetting the non-referenced flowtable destination."
    }
  ],
  "lastModified": "2026-08-25T06:18:53.000",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}