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CVE-2026-72250

Estado: RecibidaAlta (7.8)—

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

netfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag

nf_ct_frag6_reasm() slides the packet head forward to drop the IPv6 fragment header and then unconditionally advances skb->mac_header:

On the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header yet, so skb->mac_header is still the "not set" sentinel (u16)~0U. Adding sizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7), after which skb_mac_header_was_set() wrongly reports a MAC header is present and skb_mac_header() points into the headroom.

Leer descripción completaMostrar menos

The reassembler has done this unconditional add since it was introduced; it was harmless while mac_header was a bare pointer, but wrong once mac_header became a u16 offset whose unset state is the ~0U sentinel tested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c does the same relocation and does guard the adjustment; mirror the guard here.

Detalles técnicos trazas, registros y código del informe original
	skb->mac_header += sizeof(struct frag_hdr);

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 kernel local (AV:L, PR:L) sin interacción que permite escalada por corrupción de memoria en netfilter; impactos potenciales: DoS por desestabilización o corrupción de datos de red.

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

Threat Intelligence ProgramRestrict File and Directory PermissionsRemote Data StorageFilter Network TrafficExecution PreventionEncrypt Sensitive Information

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-2026-72250",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "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": "9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1",
              "lessThan": "6e8cd710ca35c576f5f2e5a396047c9ac61f75e5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1",
              "lessThan": "2a95ec21824a8ad81ad660b12231456fc0ac9830",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1",
              "lessThan": "bbcdef2061b170af45702ce6b359c02c12acfc94",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1",
              "lessThan": "cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58",
              "versionType": "git"
            },
            {
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              "lessThan": "53ef70a315420ed31581d38343684b3bf9a3c76d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1",
              "lessThan": "a58230f3a7c4f6c3261786bc1efb72c42e68cd25",
              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "00bdce2fda7e430d24cfbc96764a1b96deb31f82",
              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/ipv6/netfilter/nf_conntrack_reasm.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "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/ipv6/netfilter/nf_conntrack_reasm.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:21:52.267",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/00bdce2fda7e430d24cfbc96764a1b96deb31f82",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2a95ec21824a8ad81ad660b12231456fc0ac9830",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/53ef70a315420ed31581d38343684b3bf9a3c76d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6e8cd710ca35c576f5f2e5a396047c9ac61f75e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a58230f3a7c4f6c3261786bc1efb72c42e68cd25",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bbcdef2061b170af45702ce6b359c02c12acfc94",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58",
      "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_conntrack_reasm: guard mac_header adjustment after IPv6 defrag\n\nnf_ct_frag6_reasm() slides the packet head forward to drop the IPv6\nfragment header and then unconditionally advances skb->mac_header:\n\n\tskb->mac_header += sizeof(struct frag_hdr);\n\nOn the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header\nyet, so skb->mac_header is still the \"not set\" sentinel (u16)~0U. Adding\nsizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7),\nafter which skb_mac_header_was_set() wrongly reports a MAC header is\npresent and skb_mac_header() points into the headroom.\n\nThe reassembler has done this unconditional add since it was introduced;\nit was harmless while mac_header was a bare pointer, but wrong once\nmac_header became a u16 offset whose unset state is the ~0U sentinel\ntested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c\ndoes the same relocation and does guard the adjustment; mirror the\nguard here."
    }
  ],
  "lastModified": "2026-08-17T06:18:27.010",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}