Vulnerabilidad · Publicado 06/08/2026
Múltiples fabricantes han reportado una vulnerabilidad crítica (CVSS 10.0) en mecanismos de autenticación JWT que aceptan tokens firmados con algoritmos no configurados explícitamente. Atacantes pueden falsificar tokens JWT con algoritmos alternativos que son validados incorrectamente, permitiendo acceso no autorizado a sistemas, bases de datos y controles administrativos. Este riesgo es especialmente grave en infraestructuras cloud, plataformas de API y soluciones de identidad ampliamente usadas en LATAM.
The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported. This allows an attacker to craft a JWT with an unsupported algorithm, which is then incorrectly validated, leading to unauthorized access. Successful exploitation of this vulnerability may result in unauthorized access to the system, including the potential compromise of administrative accounts and full account takeover. The CVSS score is adjusted to 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) in single-tenant deployments, reflecting that the impact is contained within a single security authority boundary.
Score: 10/10 — Severidad: CRITICAL — Estado NIST: Received
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CWE-347
Publicado en NIST NVD.