CVE-2026-102821

Summary

Russh is a Rust SSH client and server library. Prior to 0.63.2, an authenticated remote peer can send SSH_MSG_KEXINIT without the required SSH_MSG_KEX_ECDH_INIT and then flood SSH_MSG_CHANNEL_OPEN messages while SessionKexState::InProgress prevents priority_receiver in russh/src/server/session.rs from being drained. The server continues processing network input and enqueues a ChannelOpenReply for each request on an unbounded channel, allowing one connection to grow memory until the process is terminated. This issue is fixed in version 0.63.2.

Affected Software

VendorProductVersion RangeStatus
Eugenyrussh< 0.63.2affected

Weaknesses

  • CWE-400: CWE-400: Uncontrolled Resource Consumption
  • CWE-770: CWE-770: Allocation of Resources Without Limits or Throttling

References