CVE-2026-89569

Estado: RecibidaAlta (8.8)—

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

Bluetooth: RFCOMM: serialize security confirmation handling

rfcomm_security_cfm() looks up a session on session_list and then walks its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown uses rfcomm_mutex, krfcommd can close and free the same session and DLCs concurrently:

The callback can then read a freed session list head and touch freed DLCs while updating their flags or timers.

Serialize the session lookup and DLC traversal in rfcomm_security_cfm() with rfcomm_mutex. This matches the existing RFCOMM session lifetime rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink() from tearing the objects down while the callback is using them.

Detalles técnicos trazas, registros y código del informe original

  hci_rx_work                    krfcommd
  -----------                    ---------
  rfcomm_session_get()
                                 rfcomm_lock()
                                 rfcomm_session_close()
                                   rfcomm_dlc_unlink()
                                   rfcomm_session_del()
                                     kfree(s)
                                 rfcomm_unlock()
  walk s->dlcs

KASAN reported:

  BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440
  Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89
  Workqueue: hci0 hci_rx_work
  Call Trace:
   rfcomm_security_cfm+0x41c/0x440
   hci_encrypt_cfm+0x139/0x590
   hci_encrypt_change_evt+0x37b/0xc40
   hci_event_packet+0x71b/0xb20
   hci_rx_work+0x293/0x730
  Allocated by task 69:
   rfcomm_session_add+0x9e/0x2f0
   rfcomm_run+0x44b/0x41e0
  Freed by task 69:
   kfree+0x131/0x3c0
   rfcomm_session_del+0x188/0x220
   rfcomm_run+0x1985/0x41e0

CVSS

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

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.34%
Percentil entre todas las CVEs puntuadas: 26
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.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement45 %
Impacto principalT1499.004 Application or System Exploitationimpact70 %
Impacto secundarioT1068 Exploitation for Privilege Escalationprivilege escalation55 %

Vulnerabilidad de race condition en kernel Linux (red adyacente, AV:A) sin interacción. Impacto primario: DoS (cierre de sesión/kernel panic por use-after-free), secundario: escalada si el atacante local aprovecha el estado inconsistente para ejecutar código privilegiado.

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 Application Isolation and Sandboxing Exploit Protection Update Software Vulnerability Scanning 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-2026-89569",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:A/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": 2.8
      }
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      "affectedData": [
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          "versions": [
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              "version": "6.12.109",
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              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
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            }
          ],
          "programFiles": [
            "net/bluetooth/rfcomm/core.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:40.920",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: serialize security confirmation handling\n\nrfcomm_security_cfm() looks up a session on session_list and then walks\nits DLC list without holding rfcomm_mutex. Since RFCOMM session teardown\nuses rfcomm_mutex, krfcommd can close and free the same session and DLCs\nconcurrently:\n\n  hci_rx_work                    krfcommd\n  -----------                    ---------\n  rfcomm_session_get()\n                                 rfcomm_lock()\n                                 rfcomm_session_close()\n                                   rfcomm_dlc_unlink()\n                                   rfcomm_session_del()\n                                     kfree(s)\n                                 rfcomm_unlock()\n  walk s->dlcs\n\nThe callback can then read a freed session list head and touch freed DLCs\nwhile updating their flags or timers.\n\nSerialize the session lookup and DLC traversal in rfcomm_security_cfm()\nwith rfcomm_mutex. This matches the existing RFCOMM session lifetime\nrules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()\nfrom tearing the objects down while the callback is using them.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440\n  Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89\n  Workqueue: hci0 hci_rx_work\n  Call Trace:\n   rfcomm_security_cfm+0x41c/0x440\n   hci_encrypt_cfm+0x139/0x590\n   hci_encrypt_change_evt+0x37b/0xc40\n   hci_event_packet+0x71b/0xb20\n   hci_rx_work+0x293/0x730\n  Allocated by task 69:\n   rfcomm_session_add+0x9e/0x2f0\n   rfcomm_run+0x44b/0x41e0\n  Freed by task 69:\n   kfree+0x131/0x3c0\n   rfcomm_session_del+0x188/0x220\n   rfcomm_run+0x1985/0x41e0"
    }
  ],
  "lastModified": "2026-09-14T13:19:11.727",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}