AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

SummaryA malicious SSH server can wedge an AsyncSSH client, and an authenticatedclient can wedge an AsyncSSH server, by sending a channel maximum packetsize of 0 in SSHMSGCHANNELOPENCONFIRMATION server→client orSSHMSGCHANNELOPEN client→server. AsyncSSH stores the peer-supplied valueverbatim with ...

PYSEC-2026-4026 AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

Summary A malicious SSH server can wedge an AsyncSSH client, and an authenticated client can wedge an AsyncSSH server, by sending a channel maximum packet size of 0 in SSHMSGCHANNELOPENCONFIRMATION server→client or SSHMSGCHANNELOPEN client→server. AsyncSSH stores the peer-supplied value verbatim...

AlmaLinux 9.6 [TuxCare] Security Update: libssh / libssh-config / libssh-devel Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1786549709)

The AlmaLinux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1786549709 advisory. - A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing lat...

AlmaLinux 9.2 [TuxCare] Security Update: libssh / libssh-config / libssh-devel Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1786446507)

The AlmaLinux 9.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1786446507 advisory. - A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing lat...

Rocky Linux 9.6 [TuxCare] Security Update: libssh / libssh-config / libssh-devel Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1786549709)

The Rocky Linux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1786549709 advisory. - A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing...

EUVD-2026-89204

Russh: Unbounded memory exhaustion via CHANNELOPEN flood during a client-stalled rekey...

CVE-2026-102821

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

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 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...

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 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: Uncontrolled Resource Consumption

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...

SUSE CVE-2026-62949

AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Prior to 2.24.0, processchannelopen and processchannelopenconfirmation in asyncssh/connection.py accept a peer-supplied sendpktsize value of...

GHSA-RW4J-R22C-9GC3 AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

Summary A malicious SSH server can wedge an AsyncSSH client, and an authenticated client can wedge an AsyncSSH server, by sending a channel maximum packet size of 0 in SSHMSGCHANNELOPENCONFIRMATION server→client or SSHMSGCHANNELOPEN client→server. AsyncSSH stores the peer-supplied value verbatim...

AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

Summary A malicious SSH server can wedge an AsyncSSH client, and an authenticated client can wedge an AsyncSSH server, by sending a channel maximum packet size of 0 in SSHMSGCHANNELOPENCONFIRMATION server→client or SSHMSGCHANNELOPEN client→server. AsyncSSH stores the peer-supplied value verbatim...

Infinite loop

Overview Affected versions of this package are vulnerable to Infinite loop in the SSHMSGCHANNELOPEN and SSHMSGCHANNELOPENCONFIRMATION. An attacker can cause the asyncio event loop to freeze by supplying a sendpktsize value of zero, which leads to an infinite loop that prevents further processing ...

CVE-2026-62949 AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Prior to 2.24.0, processchannelopen and processchannelopenconfirmation in asyncssh/connection.py accept a peer-supplied sendpktsize value of...

libssh: libssh: denial of service via zero advertised channel packet size

A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service...

CVE-2026-59843: Loop with Unreachable Exit Condition

A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service...