CVE-2026-116774
CVE-2026-116774 · russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 4.3 · Medium · EPSS 0.3%
- Published
- Updated
Stack: system
Affected products and versions
russh
- Versions
- >= 0.60.0, < 0.65.0: Affected
No fix published
rust-russh Debian:14
- Versions
- 0.57.1-1
- 0.57.1-2
- 0.64.1-1
- 0.64.1-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
rust-russh Ubuntu:26.10
- Versions
- 0.57.1-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published