CVE-2026-80929

Estado: RecibidaAlta (7.8)—

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

sysctl: move the "cad_pid" entry from pid_table[] to kern_reboot_table[]

cad_pid is global, and kill_cad_pid() is only used in the root namespace.

However, due to pid_table_root_permissions(), a non-root user can unshare pid/user namespaces and modify it from the child namespace. This makes no sense and is simply wrong.

Move it to kern_reboot_table[] where it logically belongs; this ensures that only GLOBAL_ROOT_UID can read/modify this sysctl.

Note that this patch doesn't preserve "#ifdef CONFIG_PROC_SYSCTL" around the "cad_pid"; CONFIG_PROC_SYSCTL selects CONFIG_SYSCTL, so it is always set when kern_reboot_table[] is compiled.

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: 0.17%
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 principalT1548 Abuse Elevation Control Mechanismprivilege escalation80 %

AV:L/PR:L/UI:N permite escalada local: usuario sin privilegios modifica cad_pid (control de acceso a Ctrl-Alt-Del) mediante namespace unshare para alterar comportamiento del sistema raíz.

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 Update Software User Account Management Threat Intelligence Program Restrict File and Directory Permissions Privileged Account Management

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-2026-80929",
  "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": "e054bcbe7e7af2baad3752f1a4916a7fffc0457e",
              "lessThan": "e8527de7fea191fda704792a56081f9009aeec37",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e054bcbe7e7af2baad3752f1a4916a7fffc0457e",
              "lessThan": "a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e054bcbe7e7af2baad3752f1a4916a7fffc0457e",
              "lessThan": "7170ca01623b399c97f2ae9d3e228badc1f25ea3",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/pid.c",
            "kernel/reboot.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.17",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/pid.c",
            "kernel/reboot.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:18:56.647",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/7170ca01623b399c97f2ae9d3e228badc1f25ea3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e8527de7fea191fda704792a56081f9009aeec37",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]\n\ncad_pid is global, and kill_cad_pid() is only used in the root namespace.\n\nHowever, due to pid_table_root_permissions(), a non-root user can unshare\npid/user namespaces and modify it from the child namespace. This makes no\nsense and is simply wrong.\n\nMove it to kern_reboot_table[] where it logically belongs; this ensures\nthat only GLOBAL_ROOT_UID can read/modify this sysctl.\n\nNote that this patch doesn't preserve \"#ifdef CONFIG_PROC_SYSCTL\" around\nthe \"cad_pid\"; CONFIG_PROC_SYSCTL selects CONFIG_SYSCTL, so it is always\nset when kern_reboot_table[] is compiled."
    }
  ],
  "lastModified": "2026-09-13T07:17:00.663",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}