CVE-2026-102821Medium· 6.5▾ TwilightPoC availableRussh 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::InProgre…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 35.8 · likelihood 0.1 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 30.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.3%
Exploit / PoC code exists
0.3% → 0.4%
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.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Affected packages:
russh <= 0.63.1Patched in:
russh 0.63.2Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-102825Low· 3.7Russh is a Rust SSH client and server library
CVE-2026-102820Medium· 6.2pageant provides a [PageantStream] type that implements [AsyncRead] and [AsyncWrite] traits and can be used to talk to a running Pageant instance
CVE-2026-102823High· 7.5Russh is a Rust SSH client and server library
CVE-2026-102824Medium· 4.3Russh is a Rust SSH client and server library
CVE-2026-102822Low· 3.7Russh is a Rust SSH client and server library
CVE-2026-116773Medium· 4.3russh's SSH client is susceptible to unbounded allocations via EXT_INFO packets