CVE-2025-40046

Estado: AplazadaAlta (8.6)—

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

io_uring/zcrx: fix overshooting recv limit

It's reported that sometimes a zcrx request can receive more than was requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for all received buffers including frag lists, but then doing recursive calls to process frag list skbs, which leads to desc->count double accounting and underflow.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
Puntuación base: 8.6

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.35%
Percentil entre todas las CVEs puntuadas: 26
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access45 %
Impacto principalT1499.004 Application or System Exploitationimpact35 %
Impacto secundarioT1005 Data from Local Systemcollection30 %

AV:N sin PR/UI sugiere T1190 remota, pero descripción técnica (bug de kernel en io_uring) reduce confianza. DoS por double accounting/underflow (A:H) es el impacto principal; C:L/I:L permiten lecturas/manipulación secundaria.

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 Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application 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 Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2025-40046",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.6,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 4.7,
        "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": "6699ec9a23f85f1764183430209c741847c45f12",
              "lessThan": "8bcc9eaf1b19f1a7029cba19f6bd4122b40f6c4f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6699ec9a23f85f1764183430209c741847c45f12",
              "lessThan": "09cfd3c52ea76f43b3cb15e570aeddf633d65e80",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "io_uring/zcrx.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.17.3",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "io_uring/zcrx.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-10-28T12:15:38.687",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/09cfd3c52ea76f43b3cb15e570aeddf633d65e80",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8bcc9eaf1b19f1a7029cba19f6bd4122b40f6c4f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/zcrx: fix overshooting recv limit\n\nIt's reported that sometimes a zcrx request can receive more than was\nrequested. It's caused by io_zcrx_recv_skb() adjusting desc->count for\nall received buffers including frag lists, but then doing recursive\ncalls to process frag list skbs, which leads to desc->count double\naccounting and underflow."
    }
  ],
  "lastModified": "2026-07-30T06:24:08.070",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}