CVE-2026-74630

Estado: RecibidaAlta (7.8)—

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

ipv6: prevent in6_dev_get() from resurrecting inet6_dev

in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed.

Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller.

Leer descripción completaMostrar menos

An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000:

It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends:

Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.

Detalles técnicos trazas, registros y código del informe original

  refcount_t: addition on 0; use-after-free.
  ip6_mc_source+0xef4/0x17e0

  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0
  Write of size 8 at addr ffff888015b50240 by task poc/1219

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.13%
Percentil entre todas las CVEs puntuadas: 2
Fecha de la puntuación: 5/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution75 %
Impacto secundarioT1499.004 Application or System Exploitationimpact60 %

Acceso local (AV:L, PR:L) con escalada de privilegios por use-after-free en kernel IPv6. Permite ejecución de código y denegación de servicio.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Filter Network Traffic

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-2026-74630",
  "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",
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  "published": "2026-08-22T16:16:35.943",
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    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\n\nin6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally\nincrements its refcount. Device teardown can clear the pointer and drop\nthe last reference between these operations. The increment then\nresurrects an object whose RCU free has already been queued, so callers\ncan use it after it is freed.\n\nUse refcount_inc_not_zero() and return NULL when the object has already\nreached zero. RCU keeps the memory accessible through the attempted\nreference acquisition, and a successful increment pins the object for\nthe caller.\n\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\nkernel reproduced the invalid reference acquisition as UID 1000:\n\n  refcount_t: addition on 0; use-after-free.\n  ip6_mc_source+0xef4/0x17e0\n\nIt was followed by the corresponding reference underflow in\nip6_mc_source(). The supplied trace from the same unpatched revision\nadditionally shows the access after the RCU read-side section ends:\n\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\n\nBug found and triaged by OpenAI Security Research and\nvalidated by Trail of Bits."
    }
  ],
  "lastModified": "2026-08-25T06:18:41.893",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}