CVE-2026-64136

Estado: AnalizadaCrítica (9.8)—

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

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()

Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifs_tcp_ses_lock for tc_lock around tc_count changes.

There was missing lock around tc_count increment inside smb2_find_smb_sess_tcon_unlocked().

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 9.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.67%
Percentil entre todas las CVEs puntuadas: 50
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 access75 %

Vulnerabilidad remota en Linux kernel (AV:N, PR:N, UI:N) con impacto crítico (C:H, I:H, A:H). Race condition en tc_count sin sincronización causa corrupción de memoria/DoS.

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

Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Filter Network Traffic Application Isolation and Sandboxing

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-64136",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "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": "953953abb66e52c224057ab91e404284fefeab62",
              "lessThan": "7df1df6f40c0720d30206aa35c0343b962350e0d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "601dd3b79769b38d30b693c40afdb2a4b7edf9d0",
              "lessThan": "13fb413ae22a37c69341918a6d651d19a9b0b9b7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3969db6b22e3d90d8c5f22ac1a7fe0350a94c136",
              "lessThan": "bf4ebdb19ff9b3cdf992b50715fe61633327416a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "96c4af418586ee9a6aab61738644366426e05316",
              "lessThan": "e374f4e496fef8168784f93a4477d67be34485fd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "96c4af418586ee9a6aab61738644366426e05316",
              "lessThan": "4d8690dace005a38e6dbde9ecce2da3ad85c7c41",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8c59eeeeffa1524ef57e173a89a1a3ff539888d5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.6.128",
              "lessThan": "6.6.142",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.12.75",
              "lessThan": "6.12.92",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.18.16",
              "lessThan": "6.18.34",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.19.6",
              "lessThan": "6.20",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2transport.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "7.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2transport.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-19T16:17:55.463",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd",
      "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\nsmb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()\n\nCommit 96c4af418586 (\"cifs: Fix locking usage for tcon fields\")\nrefactored cifs code to change cifs_tcp_ses_lock for tc_lock around\ntc_count changes.\n\nThere was missing lock around tc_count increment inside\nsmb2_find_smb_sess_tcon_unlocked()."
    }
  ],
  "lastModified": "2026-08-13T15:08:29.567",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "637728F8-A8CA-4DE9-8032-CAC1DE6B6B44",
              "versionEndExcluding": "6.6.142",
              "versionStartIncluding": "6.6.128"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FCC171CA-8EB3-4BBA-9598-7821641E468A",
              "versionEndExcluding": "6.12.92",
              "versionStartIncluding": "6.12.75"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "19854A53-434C-4733-8EA0-563B5BE89FB1",
              "versionEndExcluding": "6.18.34",
              "versionStartIncluding": "6.18.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B9C1EA03-3A8A-42C6-914D-BDC5D48CD92C",
              "versionEndExcluding": "7.0.11",
              "versionStartIncluding": "6.19.6"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}