CVE-2026-31406

Estado: AnalizadaAlta (7.8)—

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

xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()

After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.

The following is a simple race scenario:

To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().

Detalles técnicos trazas, registros y código del informe original

           cpu0                             cpu1

cleanup_net() [Round 1]
  ops_undo_list()
    xfrm_net_exit()
      xfrm_nat_keepalive_net_fini()
        cancel_delayed_work_sync(nat_keepalive_work);
      xfrm_state_fini()
        xfrm_state_flush()
          xfrm_state_delete(x)
            __xfrm_state_delete(x)
              xfrm_nat_keepalive_state_updated(x)
                schedule_delayed_work(nat_keepalive_work);
  rcu_barrier();
  net_complete_free();
  net_passive_dec(net);
    llist_add(&net->defer_free_list, &defer_free_list);

cleanup_net() [Round 2]
  rcu_barrier();
  net_complete_free()
    kmem_cache_free(net_cachep, net);
                                     nat_keepalive_work()
                                       // on freed net

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: 0.18%
Percentil entre todas las CVEs puntuadas: 6
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 principalT1499.004 Application or System Exploitationimpact75 %

Vulnerabilidad local (AV:L, PR:L) sin interacción: escalada de privilegios por race condition en liberación de memoria. Use-after-free en nat_keepalive_work permite ejecución con contexto elevado (C:H, I:H, A:H). Impacto DoS por corrupción de memoria y potencial EOP.

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 Filter Network Traffic Execution Prevention Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-31406",
  "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": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "lessThan": "32d0f44c2f14d60fe8e920e69a28c11051543ec1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "lessThan": "2255ed6adbc3100d2c4a83abd9d0396d04b87792",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "lessThan": "21f2fc49ca6faa393c31da33b8a4e6c41fc84c13",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "lessThan": "daf8e3b253aa760ff9e96c7768a464bc1d6b3c90",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/xfrm/xfrm_nat_keepalive.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.11",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.80",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19.11",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/xfrm/xfrm_nat_keepalive.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-04-06T08:16:38.457",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/21f2fc49ca6faa393c31da33b8a4e6c41fc84c13",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2255ed6adbc3100d2c4a83abd9d0396d04b87792",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/32d0f44c2f14d60fe8e920e69a28c11051543ec1",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/daf8e3b253aa760ff9e96c7768a464bc1d6b3c90",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()\n\nAfter cancel_delayed_work_sync() is called from\nxfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining\nstates via __xfrm_state_delete(), which calls\nxfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.\n\nThe following is a simple race scenario:\n\n           cpu0                             cpu1\n\ncleanup_net() [Round 1]\n  ops_undo_list()\n    xfrm_net_exit()\n      xfrm_nat_keepalive_net_fini()\n        cancel_delayed_work_sync(nat_keepalive_work);\n      xfrm_state_fini()\n        xfrm_state_flush()\n          xfrm_state_delete(x)\n            __xfrm_state_delete(x)\n              xfrm_nat_keepalive_state_updated(x)\n                schedule_delayed_work(nat_keepalive_work);\n  rcu_barrier();\n  net_complete_free();\n  net_passive_dec(net);\n    llist_add(&net->defer_free_list, &defer_free_list);\n\ncleanup_net() [Round 2]\n  rcu_barrier();\n  net_complete_free()\n    kmem_cache_free(net_cachep, net);\n                                     nat_keepalive_work()\n                                       // on freed net\n\nTo prevent this, cancel_delayed_work_sync() is replaced with\ndisable_delayed_work_sync()."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nxfrm: Corrige la reprogramación del trabajo después de la cancelación en xfrm_nat_keepalive_net_fini()\n\nDespués de que se llama a cancel_delayed_work_sync() desde xfrm_nat_keepalive_net_fini(), xfrm_state_fini() vacía los estados restantes a través de __xfrm_state_delete(), que llama a xfrm_nat_keepalive_state_updated() para reprogramar nat_keepalive_work.\n\nEl siguiente es un escenario de carrera simple:\n\n           cpu0                             cpu1\n\ncleanup_net() [Ronda 1]\n  ops_undo_list()\n    xfrm_net_exit()\n      xfrm_nat_keepalive_net_fini()\n        cancel_delayed_work_sync(nat_keepalive_work);\n      xfrm_state_fini()\n        xfrm_state_flush()\n          xfrm_state_delete(x)\n            __xfrm_state_delete(x)\n              xfrm_nat_keepalive_state_updated(x)\n                schedule_delayed_work(nat_keepalive_work);\n  rcu_barrier();\n  net_complete_free();\n  net_passive_dec(net);\n    llist_add(&net -> defer_free_list, &defer_free_list);\n\ncleanup_net() [Ronda 2]\n  rcu_barrier();\n  net_complete_free()\n    kmem_cache_free(net_cachep, net);\n                                     nat_keepalive_work()\n                                       // en net liberado\n\nPara evitar esto, cancel_delayed_work_sync() se reemplaza con disable_delayed_work_sync()."
    }
  ],
  "lastModified": "2026-07-24T22:10:00.140",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3C886EDB-88C5-47BE-9133-37C769192535",
              "versionEndExcluding": "6.12.80",
              "versionStartIncluding": "6.11"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE",
              "versionEndExcluding": "6.18.21",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7",
              "versionEndExcluding": "6.19.11",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}