CVE-2025-26466

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

Se ha descubierto un fallo en el paquete OpenSSH. Por cada paquete ping que recibe el servidor SSH, se asigna un paquete pong en un búfer de memoria y se almacena en una cola de paquetes. Solo se libera cuando finaliza el intercambio de claves entre el servidor y el cliente. Un cliente malintencionado puede seguir enviando dichos paquetes, lo que provoca un aumento descontrolado del consumo de memoria en el lado del servidor. En consecuencia, el servidor puede dejar de estar disponible, lo que da lugar a un ataque de denegación de servicio.