ssh has begun failing when connecting to servers running OpenSSH_8.9p1, LibreSSL 3.3.6. and Mac is running OpenSSH_10.2p1, LibreSSL 3.3.6.
The last line of the debug output running ssh -vvvv is:
debug3: ssh_get_authentication_socket_path: path '/var/run/com.apple.launchd.YUMtRKxnS6/Listeners'
I can connect with older versions of OSX with both password and ssh key so it’s probably not an issue with the servers but with something that changed in macOS.
Per Linc this is the debug output. I replaced my username with myusername. I am aware that the usernam is now case sensitive. And the URL with 255.255.255.255
debug1: OpenSSH_10.2p1, LibreSSL 3.3.6
debug3: Running on Darwin 25.4.0 Darwin Kernel Version 25.4.0: Thu Mar 19 19:32:36 PDT 2026; root:xnu-12377.101.15~1/RELEASE_ARM64_T8103 arm64
debug3: Started with: ssh -vvvv [email protected]
debug1: Reading configuration data /Users/myusername/.ssh/config
debug1: /Users/myusername/.ssh/config line 1: Applying options for 255.255.255.255
debug1: /Users/myusername/.ssh/config line 12: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 21: include /etc/ssh/ssh_config.d/* matched no files
debug1: /etc/ssh/ssh_config line 54: Applying options for *
debug2: resolve_canonicalize: hostname 255.255.255.255 is address
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/Users/myusername/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/Users/myusername/.ssh/known_hosts2'
debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling
debug3: channel_clear_timeouts: clearing
debug3: ssh_connect_direct: entering
debug1: Connecting to 255.255.255.255 [255.255.255.255] port 22.
debug3: set_sock_tos: set socket 3 IP_TOS 0xb8
debug1: Connection established.
debug1: loaded pubkey from /Users/myusername/.ssh/id_ed25519: ED25519 SHA256:f1e1jpj2rmTZcAd8Kiq4Q/haVK3KDrMZp5w6ZuaUNNg
debug1: identity file /Users/myusername/.ssh/id_ed25519 type 2
debug1: no identity pubkey loaded from /Users/myusername/.ssh/id_ed25519
debug1: Local version string SSH-2.0-OpenSSH_10.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.9p1 Ubuntu-3ubuntu0.14
debug1: compat_banner: match: OpenSSH_8.9p1 Ubuntu-3ubuntu0.14 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 255.255.255.255:22 as 'myusername'
debug3: record_hostkey: found key type ED25519 in file /Users/myusername/.ssh/known_hosts:14
debug3: load_hostkeys_file: loaded 1 keys from 255.255.255.255
debug1: load_hostkeys: fopen /Users/myusername/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug3: order_hostkeyalgs: have matching best-preference key type [email protected], using HostkeyAlgorithms verbatim
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: mlkem768x25519-sha256,sntrup761x25519-sha512,[email protected],curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c,[email protected]
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256
debug2: ciphers ctos: [email protected],[email protected],[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: ciphers stoc: [email protected],[email protected],[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,[email protected],diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,[email protected]
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug3: kex_choose_conf: will use strict KEX ordering
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: [email protected] MAC: compression: none
debug1: kex: client->server cipher: [email protected] MAC: compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:Nc8wf5d4kpIjTbuRJ11BcdOb/05x6gOWiFRZVHov1q8
debug3: record_hostkey: found key type ED25519 in file /Users/myusername/.ssh/known_hosts:14
debug3: load_hostkeys_file: loaded 1 keys from 255.255.255.255
debug1: load_hostkeys: fopen /Users/myusername/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: Host '255.255.255.255' is known and matches the ED25519 host key.
debug1: Found key in /Users/myusername/.ssh/known_hosts:14
debug3: send packet: type 21
debug1: ssh_packet_send2_wrapped: resetting send seqnr 3
debug2: ssh_set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: ssh_packet_read_poll2: resetting read seqnr 3
debug1: SSH2_MSG_NEWKEYS received
debug2: ssh_set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug2: KEX algorithms: mlkem768x25519-sha256,sntrup761x25519-sha512,[email protected],curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c,[email protected]
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256
debug2: ciphers ctos: [email protected],[email protected],[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: ciphers stoc: [email protected],[email protected],[email protected],aes128-ctr,aes192-ctr,aes256-ctr
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug3: kex_input_ext_info: extension server-sig-algs
debug1: kex_ext_info_client_parse: server-sig-algs=[email protected],ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected]>
debug3: kex_input_ext_info: extension [email protected]
debug1: kex_ext_info_check_ver: [email protected]=<0>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug3: ssh_get_authentication_socket_path: path '/var/run/com.apple.launchd.YUMtRKxnS6/Listeners'
