{"id":"UBUNTU-CVE-2026-116773","details":"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.","modified":"2026-10-28T20:17:46.253734794Z","published":"2026-10-27T21:18:00Z","upstream":["CVE-2026-116773"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-116773"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-116773"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0"}],"affected":[{"package":{"name":"rust-russh","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/rust-russh?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.57.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-russh-dev","binary_version":"0.57.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116773.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"medium"}]}