{"id":"CVE-2026-102821","sourceIdentifier":"security-advisories@github.com","published":"2026-09-29T19:17:23.993","lastModified":"2026-09-30T20:17:23.793","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.63.2","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-30T19:34:47.748081Z","id":"CVE-2026-102821","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-400"},{"lang":"en","value":"CWE-770"}]}],"references":[{"url":"https://github.com/Eugeny/russh/commit/a282af361ac99bc76b80876d1aae128e89dbf66b","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.63.2","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}