CVE-2026-32314: Protocol Yamux

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Yamux is a stream multiplexer over reliable, ordered connections such as TCP/IP. Prior to 0.13.10, the Rust implementation of Yamux can panic when processing a crafted inbound Data frame that sets SYN and uses a body length greater than DEFAULT_CREDIT (e.g. 262145). On the first packet of a new inbound stream, stream state is created and a receiver is queued before oversized-body validation completes. When validation fails, the temporary stream is dropped and cleanup may call remove(...).expect("stream not found"), triggering a panic in the connection state machine. This is remotely reachable over a normal Yamux session and does not require authentication. This vulnerability is fixed in 0.13.10.

Affected products

• Protocol Yamux: before 0.13.10 (fixed in 0.13.10)

Published 2026-03-16. Last modified 2026-06-17.