CVE-2026-9704
Keycloak: keycloak: privilege escalation due to oversized subject_token jwt
Vexday Risk Score
13Bajo
Decisión SSVC (CISA)
Track
Sin señal de explotación → monitorear
CVSS 6.8EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado
Ciclo de vida
27 may 2026Publicada en NVD
Recomendación: Monitorear — sin señal de explotación por ahora.
A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Productos afectados
Red Hat · Red Hat build of Keycloak 26.6Red Hat · Red Hat build of Keycloak 26.6.3¿Quieres saber si tu infraestructura está expuesta a esto?
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