Looks like ed25519 was added in May 10th, 2015. [1]
We claim version: SSH-2.0-PuTTY_Snapshot_2015_11_08.b003e5c
Server version: SSH-2.0-OpenSSH_6.7p1 Debian-5
Using SSH protocol version 2
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-ed25519 256 <fingerprint>
Initialised ChaCha20 client->server encryption
Initialised Poly1305 client->server MAC algorithm (in ETM mode) (required by cipher)
Initialised ChaCha20 server->client encryption
Initialised Poly1305 server->client MAC algorithm (in ETM mode) (required by cipher)
I'm no expert, and this might not be what you are talking about, but to my untrained eye, it does?
Now, to get back on topic, they believe that the attack would already need access to the server.
"To exploit a vulnerability in the terminal emulator, an attacker must be able to insert a carefully crafted escape sequence into the terminal stream. For a PuTTY SSH session, this must be before encryption, so the attacker likely needs access to the server you're connecting to. For instance, an attacker on a multi-user machine that you connect to could trick you into running cat on a file they control containing a malicious escape sequence. (Unix write(1) is not a vector for this, if implemented correctly.)"
I'm no expert, and this might not be what you are talking about, but to my untrained eye, it does?
Now, to get back on topic, they believe that the attack would already need access to the server.
"To exploit a vulnerability in the terminal emulator, an attacker must be able to insert a carefully crafted escape sequence into the terminal stream. For a PuTTY SSH session, this must be before encryption, so the attacker likely needs access to the server you're connecting to. For instance, an attacker on a multi-user machine that you connect to could trick you into running cat on a file they control containing a malicious escape sequence. (Unix write(1) is not a vector for this, if implemented correctly.)"
[1] http://tartarus.org/~simon-git/gitweb/?p=putty-wishlist.git;...