CVE-2026-74615

Estado: RecibidaAlta (8.8)—

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

vxlan: do not arm the ageing timer on a device that is down

vxlan_changelink() arms vxlan->age_timer whenever the requested ageing interval differs from the configured one:

There is no netif_running() test, so the timer is armed even on a device that was never brought up. The only synchronous cancel in the driver is the timer_delete_sync() in vxlan_stop(), which is .ndo_stop. netif_close_many() drops devices without IFF_UP before __dev_close_many() runs, so that cancel is skipped for such a device.

vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a member of struct vxlan_dev, so free_netdev() releases the allocation the timer lives in while it is still queued on a timer_base. expire_timers() unlinks the entry before it loads timer->function, so the timer core writes through the freed object's list pointers:

Leer descripción completaMostrar menos

The rtnl operations involved are netns-scoped, so an unprivileged user can perform them in a new user and network namespace.

Arming the timer on a down device never had an effect: vxlan_cleanup() returns early on !netif_running(), and vxlan_open() arms the timer for any non-zero interval once the device is brought up. Add the missing test.

Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

Detalles técnicos trazas, registros y código del informe original

	if (conf.age_interval != vxlan->cfg.age_interval)
		mod_timer(&vxlan->age_timer, jiffies);

  BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654
  Write of size 8 at addr ffff00001adace68 by task true/192
   __asan_store8+0x84/0xac
   __run_timers+0x208/0x654
   run_timer_softirq+0x154/0x18c
  Allocated by task 189:
   alloc_netdev_mqs+0x64/0x720
   rtnl_create_link+0x4ac/0x520
   rtnl_newlink+0x758/0xd00
  Freed by task 191:
   netdev_release+0x40/0x58
   netdev_run_todo+0x4a4/0x8c0
   rtnl_dellink+0x200/0x4e8

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Puntuación base: 8.8

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: 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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation95 %
Impacto principalT1499.004 Application or System Exploitationimpact85 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact60 %

Escalada local sin interacción (AV:L, PR:L, UI:N) en kernel Linux. Uso-después-de-liberación mediante operaciones rtnl en namespaces imprivilegiados causa DoS de memoria y corrupción de datos.

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 Program Restrict File and Directory Permissions Remote Data Storage Filter Network Traffic Execution Prevention Encrypt 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 Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-74615",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 2
      }
    ]
  },
  "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": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "be44d79d14d7f9ae7c8ffb7272142005341b5123",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "26c179d47403d2f919ee914cc02c31d896b59fee",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "9dc561f0522c35bdd66e0646a748814a138ec4ca",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "619dd29045e439d0b0f8c6d4fec1af447a050680",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "6b095e99b9e67ea31f0c4b00260e010898253519",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "46bb297ad77680e009244f067f27d51cf5b8c7cf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "6b4119af544996a545cf84b16f1dbce829ba0de8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "40051c4dcad5b374156ad9cceae8d15c0ef1cb95",
              "lessThan": "b37971686ec59fb027fa4910ba16805e68fddb97",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/net/vxlan/vxlan_core.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": "5.10.265",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "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": [
            "drivers/net/vxlan/vxlan_core.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:34.143",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/26c179d47403d2f919ee914cc02c31d896b59fee",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/46bb297ad77680e009244f067f27d51cf5b8c7cf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/619dd29045e439d0b0f8c6d4fec1af447a050680",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6b095e99b9e67ea31f0c4b00260e010898253519",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6b4119af544996a545cf84b16f1dbce829ba0de8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9dc561f0522c35bdd66e0646a748814a138ec4ca",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b37971686ec59fb027fa4910ba16805e68fddb97",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/be44d79d14d7f9ae7c8ffb7272142005341b5123",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not arm the ageing timer on a device that is down\n\nvxlan_changelink() arms vxlan->age_timer whenever the requested ageing\ninterval differs from the configured one:\n\n\tif (conf.age_interval != vxlan->cfg.age_interval)\n\t\tmod_timer(&vxlan->age_timer, jiffies);\n\nThere is no netif_running() test, so the timer is armed even on a device\nthat was never brought up.  The only synchronous cancel in the driver is\nthe timer_delete_sync() in vxlan_stop(), which is .ndo_stop.\nnetif_close_many() drops devices without IFF_UP before\n__dev_close_many() runs, so that cancel is skipped for such a device.\n\nvxlan_setup() sets dev->needs_free_netdev = true and age_timer is a\nmember of struct vxlan_dev, so free_netdev() releases the allocation the\ntimer lives in while it is still queued on a timer_base.\nexpire_timers() unlinks the entry before it loads timer->function, so\nthe timer core writes through the freed object's list pointers:\n\n  BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654\n  Write of size 8 at addr ffff00001adace68 by task true/192\n   __asan_store8+0x84/0xac\n   __run_timers+0x208/0x654\n   run_timer_softirq+0x154/0x18c\n  Allocated by task 189:\n   alloc_netdev_mqs+0x64/0x720\n   rtnl_create_link+0x4ac/0x520\n   rtnl_newlink+0x758/0xd00\n  Freed by task 191:\n   netdev_release+0x40/0x58\n   netdev_run_todo+0x4a4/0x8c0\n   rtnl_dellink+0x200/0x4e8\n\nThe rtnl operations involved are netns-scoped, so an unprivileged user\ncan perform them in a new user and network namespace.\n\nArming the timer on a down device never had an effect: vxlan_cleanup()\nreturns early on !netif_running(), and vxlan_open() arms the timer for\nany non-zero interval once the device is brought up.  Add the missing\ntest.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>"
    }
  ],
  "lastModified": "2026-08-25T06:18:39.610",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}