CVE-2026-78662: Golang Crypto

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.

Affected products

• Golang Crypto: before 0.56.0 (fixed in 0.56.0)

Published 2026-09-02. Last modified 2026-09-04.