CVE-2026-74649

Estado: RecibidaAlta (8.8)—

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

staging: rtl8723bs: fix missing shared-key auth challenge length check

The WEP shared-key authentication handler uses the challenge-text element's attacker-controlled length without checking it against the fixed 128-byte chg_txt buffer.

In OnAuthClient() the length from rtw_get_ie() - up to 255 - is used to perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a malicious AP sending a malformed WLAN_EID_CHALLENGE element can overflow/underfill chg_txt by up to 127 bytes. It is reachable over the air, before association, during shared-key authentication. In the case of an overflow, the driver can write out of bounds. In the case of an underfill, the driver can echo stale buffer memory.

Leer descripción completaMostrar menos

The challenge text is defined to be exactly 128 octets, which is already provided as the WLAN_AUTH_CHALLENGE_LEN define; require the element to be exactly that length before use.

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: 0.46%
Percentil entre todas las CVEs puntuadas: 38
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.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement90 %
Impacto principalT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto secundarioT1005 Data from Local Systemcollection75 %

Buffer overflow en controlador Wi-Fi alcanzable por red adyacente (AV:A) sin autenticación previa. Desbordamiento permite ejecución de código (escalada) o lectura de memoria (información sensible).

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

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  "id": "CVE-2026-74649",
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        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          "version": "3.1",
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          "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",
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    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix missing shared-key auth challenge length check\n\nThe WEP shared-key authentication handler uses the challenge-text\nelement's attacker-controlled length without checking it against the\nfixed 128-byte chg_txt buffer.\n\nIn OnAuthClient() the length from rtw_get_ie() - up to 255 - is used\nto perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a\nmalicious AP sending a malformed WLAN_EID_CHALLENGE element can\noverflow/underfill chg_txt by up to 127 bytes. It is reachable over the\nair, before association, during shared-key authentication. In the case\nof an overflow, the driver can write out of bounds. In the case of an\nunderfill, the driver can echo stale buffer memory.\n\nThe challenge text is defined to be exactly 128 octets, which is\nalready provided as the WLAN_AUTH_CHALLENGE_LEN define; require the\nelement to be exactly that length before use."
    }
  ],
  "lastModified": "2026-08-25T06:18:45.130",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}