CVE-2026-116773

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 3.1

4.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

CWE

CWE-770

Published

2026-10-27

Modified

2026-10-27

Record from

the NVD, synced 2026-10-27

References

• https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75
• https://github.com/Eugeny/russh/releases/tag/v0.65.0
• https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg

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