CVE-2026-116773

CVE-2026-116773 · russh's SSH client is susceptible to unbounded allocations via EXT_INFO packets

This page contains facts from public vulnerability sources. Check the original advisory before updating.

russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0.

CVSS 4.3 · Medium · EPSS 0.3%

Published

2026-10-27T20:23:25.559Z

Updated

2026-10-27T20:23:47.305Z

Stack: system

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