{"id":"CVE-2026-116774","sourceIdentifier":"security-advisories@github.com","published":"2026-10-27T21:18:05.933","lastModified":"2026-10-28T17:18:06.990","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From 0.60.0 until 0.65.0, channel-open parsing accepts a peer-declared maximum_packet_size of zero and passes it into ChannelTx::poll_writable in russh/src/channels/io/tx.rs. The Channel::data, Channel::make_writer, and Channel::into_stream asynchronous write paths then calculate a writable size of zero and remain pending forever because window adjustments cannot satisfy a static zero packet maximum. An authenticated client can strand server writes, and a malicious server can strand client writes, allowing affected tasks, channels, and connections to accumulate without surfacing an error. This issue is fixed in version 0.65.0."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"Eugeny","product":"russh","versions":[{"version":">= 0.60.0, < 0.65.0","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:L","baseScore":4.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":2.8,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-10-28T14:34:53.983359Z","id":"CVE-2026-116774","options":[{"exploitation":"none"},{"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-835"}]}],"references":[{"url":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","source":"security-advisories@github.com"}]}