{"id":"CVE-2026-102821","revision":"b548064e71ea488ebe769e61463c09ad","records":[{"revision":"b548064e71ea488ebe769e61463c09ad","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-102821","aliases":[],"title":"Russh: Unbounded memory exhaustion via CHANNEL_OPEN flood during a client-stalled rekey","description":"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.","state":0,"publishedAt":"2026-09-29T18:21:21.858+00:00","modifiedAt":"2026-09-30T19:35:02.962+00:00","affected":[{"ecosystem":"Vendor product","name":"russh","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Eugeny\",\n                    \"product\": \"russh\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 0.63.2\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5,"severity":"MEDIUM"}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw","https://github.com/Eugeny/russh/commit/a282af361ac99bc76b80876d1aae128e89dbf66b","https://github.com/Eugeny/russh/releases/tag/v0.63.2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-102821","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-102821","identifiers":["CVE-2026-102821"]},"retained":false,"historicalAffected":[]}],"coverage":[]}