CVE-2026-102821 Russh: Unbounded memory exhaustion via CHANNEL_OPEN flood during a client-stalled rekey

Russh is a Rust SSH client and server library. Prior to 0.63.2, an authenticated remote peer can send SSHMSGKEXINIT without the required SSHMSGKEXECDHINIT and then flood SSHMSGCHANNELOPEN messages while SessionKexState::InProgress prevents priorityreceiver in russh/src/server/session.rs from bein...

CVE-2026-102821

The Russh Rust SSH library (prior to version 0.63.2 ) is vulnerable to unbounded memory exhaustion during a client-stalled rekey. An authenticated remote peer can send SSH_MSG_KEXINIT without the required SSH_MSG_KEX_ECDH_INIT and flood SSH_MSG_CHANNEL_OPEN messages. Because SessionKexState::InPr...