An established connection was aborted by the server, ecdh-sha2-nistp256

[m0a0k0s]

After updating to 2025.0.0 start receiving ' An established connection was aborted by the server ' error.

at Renci.SshNet.Session.WaitOnHandle(WaitHandle waitHandle, TimeSpan timeout)
at Renci.SshNet.Session.WaitOnHandle(WaitHandle waitHandle)
at Renci.SshNet.Session.ConnectAsync(CancellationToken cancellationToken)
at Renci.SshNet.BaseClient.CreateAndConnectSessionAsync(CancellationToken cancellationToken)
at Renci.SshNet.BaseClient.ConnectAsync(CancellationToken cancellationToken)

[Rob-Hague]

hmm, there were not really any changes to ECDH key exchange between 2024.2.0 and 2025.0.0 so don't have an obvious idea

what version of .NET is the app using? and does the error happen every time?

[m0a0k0s]

net 9.0, happens every time in new version

[Rob-Hague]

is the server publicly reachable, or can you send the packet trace?

[m0a0k0s]

I've just sent the address in the email.

[Rob-Hague]

The issue was DSA removal (#1558). Apparently the library does not check for matching host key algorithms before continuing the key exchange, causing misleading/less informative issues like this one. That could be improved