{"id":"CVE-2026-116774","revision":"c62ab083ca8f4edb9ea0a60cb04648b3","records":[{"revision":"c62ab083ca8f4edb9ea0a60cb04648b3","observedAt":"2026-10-28T17:46:48.824+00:00","statement":{"source":"cve-program","id":"CVE-2026-116774","aliases":[],"title":"russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)","description":"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.","state":0,"publishedAt":"2026-10-27T20:25:26.914+00:00","modifiedAt":"2026-10-28T16:13:18.607+00:00","affected":[{"ecosystem":"Vendor product","name":"russh","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Eugeny\",\n                    \"product\": \"russh\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 0.60.0, < 0.65.0\",\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:L","score":4.3,"severity":"MEDIUM"}],"references":["https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","https://github.com/Eugeny/russh/releases/tag/v0.65.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116774","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-116774","identifiers":["CVE-2026-116774"]},"retained":false,"historicalAffected":[]}],"coverage":[]}