CVE-2026-49421

Estado: AnalizadaAlta (7.1)—

The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup. The flag was silently dropped, so path resolution was not actually restricted.

A process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory. A caller relying on this flag for path containment may delete files outside the intended directory tree.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Puntuación base: 7.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.13%
Percentil entre todas las CVEs puntuadas: 2
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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1485 Data Destructionimpact75 %
Impacto secundarioT1561.002 Disk Structure Wipeimpact70 %

Vulnerabilidad local sin interacción (AV:L, UI:N, PR:L) que permite escalada: el kernel ignora AT_RESOLVE_BENEATH, permitiendo a un proceso con privilegios locales eliminar archivos fuera del árbol previsto, afectando integridad y disponibilidad de datos críticos del sistema.

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

Data Backup User Account Management Threat Intelligence Program Multi-factor Authentication Execution Prevention Application Isolation and Sandboxing

Tecnologías afectadas (1)

Freebsd — Freebsd

CWE

CWE-273

Referencias

https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc

JSON original (NVD)

Mostrar

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