{"id":"CVE-2026-116774","published":"2026-10-27T21:18:05.933","lastModified":"2026-10-27T21:18:06.060","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.","cvssScore":4.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","cwes":["CWE-400","CWE-835"],"vendors":[],"products":[],"references":[{"url":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","tags":[]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","tags":[]},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","tags":[]}],"exploitRefs":[{"url":"https://github.com/Eugeny/russh/commit/39cb9dbaa37caf555d34c6c22efa3bbbff9e186c","tags":[]},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.65.0","tags":[]},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-fw5c-8223-6h42","tags":[]}],"hasPoc":true,"ai":null}