VDB
Sign up

GO-2026-6354

Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh

Quick fix

GO-2026-6354 — golang.org/x/crypto: upgrade to the fixed version with the command below.

go get golang.org/x/crypto@v0.56.0

Details

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.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go/golang.org/x/crypto
Introduced in: 0Fixed in: 0.56.0
Fixgo get golang.org/x/crypto@v0.56.0

References