FreeBSD source tree https://cgit-dev.freebsd.org/src/atom?h=main 2026-07-09T17:17:11Z 2026-07-09T17:17:11Z Ed Maste emaste@FreeBSD.org 2026-07-09T17:17:11Z urn:sha1:bb5c77e9d281d6def6835d48249898764bc6a5fe Full release notes are available at https://www.openssh.com/txt/release-10.4 Selected highlights from the release notes: Potentially-incompatible changes -------------------------------- * sshd(8): configuration dump mode ("sshd -G") now writes directives in mixed case (e.g. "PubkeyAuthentication") whereas previously it emitted only lower-case names. * ssh(1), sshd(8): make the transport protocol stricter by disconnecting if the peer sends non-KEX messages during a post- authentication key re-exchange. Previously a malicious peer could continue sending non-key exchange messages without penalty. These would be buffered, causing memory to be wasted up until the connection terminated or the server/client hit a memory limit. Implementations that do not restrict messages sent during key exchange as per RFC4253 section 7.1 may be disconnected. Reported by Marko Jevtic. Changes since OpenSSH 10.3 ========================== This release contains a number of security fixes as well as general bugfixes and a couple of new features. Security ======== * sftp(1): when downloading files on the command-line using "sftp host:/path .", a malicious server could cause the file to be downloaded to an unexpected location. This issue was identified by the Swival Security Scanner. * scp(1): when copying files between two remote destinations, do not allow a malicious server to write files to the parent directory of the intended target directory. This issue was identified by the Swival Security Scanner. * sshd(8): DisableForwarding=yes didn't override PermitTunnel=yes as it was documented to do. Note that PermitTunnel is not enabled by default. Reported independently by Huzaifa Sidhpurwala of Redhat and Marko Jevtic. * sshd(8): avoid a potential pre-authentication denial of service when GSSAPIAuthentication was enabled (this feature is off by default). This was not mitigated by MaxAuthTries, but would be penalised by PerSourcePenalties. This was reported by Manfred Kaiser of the milCERT AT (Austrian Ministry of Defence). * sshd(8): fix a number of cases where the minimum authentication delay was not being enforced. Reported by the Orange Cyberdefense Vulnerability Team. * ssh(1): fix a possible client-side use-after-free if the server changes its host key during a key reexchange. This was reported by Zhenpeng (Leo) Lin of Depthfirst. New features ------------ * All: add experimental support for a composite post-quantum signature scheme that combines ML-DSA 44 and Ed25519 as specified in draft-miller-sshm-mldsa44-ed25519-composite-sigs. This scheme is not enabled by default. To use it, you'll need to add it to HostKeyAlgorithms, PubkeyAcceptedAlgorithms, etc. Keys may be generated using "ssh-keygen -t mldsa44-ed25519". Bugfixes -------- * sshd(8): avoid sending observably different messages for valid vs invalid users in GSSAPIAuthentication (disabled by default). * ssh(1), sshd(8): fix several bugs that incorrectly classified bulk traffic as interactive. bz3972, bz3958 * ssh-keygen(1), ssh-add(1): skip unsupported key types when downloading resident keys from a FIDO token. Previously, downloads would abort when one was encountered. GHPR657 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58083 2026-05-14T18:59:30Z Ed Maste emaste@FreeBSD.org 2026-05-14T18:59:30Z urn:sha1:2574974648c68c738aec3ff96644d888d7913a37 Full release notes are available at https://www.openssh.com/txt/release-10.3 Selected highlights from the release notes: * ssh(1), sshd(8): remove bug compatibility for implementations that don't support rekeying. If such an implementation tries to interoperate with OpenSSH, it will now eventually fail when the transport needs rekeying. * ssh(1), sshd(8): support IANA-assigned codepoints for SSH agent forwarding, as per draft-ietf-sshm-ssh-agent. Support for the new names is advertised via the EXT_INFO message. If a server offers support for the new names, then they are used preferentially. * ssh(1): add a ~I escape option that shows information about the current SSH connection. * sshd(8): add 'invaliduser' penalty to PerSourcePenalties, which is applied to login attempts for usernames that do not match real accounts. Defaults to 5s to match 'authfail' but allows administrators to block such attempts for longer if desired. * Support the ed25519 signature scheme via libcrypto. Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D56999 2025-02-19T17:20:44Z Ed Maste emaste@FreeBSD.org 2025-02-19T17:20:44Z urn:sha1:0fdf8fae8b569bf9fff3b5171e669dcd7cf9c79e Highlights from the release notes are reproduced below. Some security and bug fixes were previously merged into FreeBSD and have been elided. See the upstream release notes for full details (https://www.openssh.com/releasenotes.html). --- Future deprecation notice ========================= OpenSSH plans to remove support for the DSA signature algorithm in early 2025. Potentially-incompatible changes -------------------------------- * sshd(8): the server will now block client addresses that repeatedly fail authentication, repeatedly connect without ever completing authentication or that crash the server. See the discussion of PerSourcePenalties below for more information. Operators of servers that accept connections from many users, or servers that accept connections from addresses behind NAT or proxies may need to consider these settings. * sshd(8): the server has been split into a listener binary, sshd(8), and a per-session binary "sshd-session". This allows for a much smaller listener binary, as it no longer needs to support the SSH protocol. As part of this work, support for disabling privilege separation (which previously required code changes to disable) and disabling re-execution of sshd(8) has been removed. Further separation of sshd-session into additional, minimal binaries is planned for the future. * sshd(8): several log messages have changed. In particular, some log messages will be tagged with as originating from a process named "sshd-session" rather than "sshd". * ssh-keyscan(1): this tool previously emitted comment lines containing the hostname and SSH protocol banner to standard error. This release now emits them to standard output, but adds a new "-q" flag to silence them altogether. * sshd(8): (portable OpenSSH only) sshd will no longer use argv[0] as the PAM service name. A new "PAMServiceName" sshd_config(5) directive allows selecting the service name at runtime. This defaults to "sshd". bz2101 New features ------------ * sshd(8): sshd(8) will now penalise client addresses that, for various reasons, do not successfully complete authentication. This feature is controlled by a new sshd_config(5) PerSourcePenalties option and is on by default. * ssh(8): allow the HostkeyAlgorithms directive to disable the implicit fallback from certificate host key to plain host keys. Portability ----------- * sshd(8): expose SSH_AUTH_INFO_0 always to PAM auth modules unconditionally. The previous behaviour was to expose it only when particular authentication methods were in use. * ssh(1), ssh-agent(8): allow the presence of the WAYLAND_DISPLAY environment variable to enable SSH_ASKPASS, similarly to the X11 DISPLAY environment variable. GHPR479 --- Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D48914 2023-08-11T03:10:18Z Ed Maste emaste@FreeBSD.org 2023-08-11T03:10:18Z urn:sha1:535af610a4fdace6d50960c0ad9be0597eea7a1b Excerpts from the release notes: * ssh-agent(1): PKCS#11 modules must now be specified by their full paths. Previously dlopen(3) could search for them in system library directories. * ssh(1): allow forwarding Unix Domain sockets via ssh -W. * ssh(1): add support for configuration tags to ssh(1). This adds a ssh_config(5) "Tag" directive and corresponding "Match tag" predicate that may be used to select blocks of configuration similar to the pf.conf(5) keywords of the same name. * ssh(1): add a "match localnetwork" predicate. This allows matching on the addresses of available network interfaces and may be used to vary the effective client configuration based on network location. * ssh-agent(1): improve isolation between loaded PKCS#11 modules by running separate ssh-pkcs11-helpers for each loaded provider. * ssh-agent(1), ssh(1): improve defences against invalid PKCS#11 modules being loaded by checking that the requested module contains the required symbol before loading it. * ssh(1): don't incorrectly disable hostname canonicalization when CanonicalizeHostname=yes and ProxyJump was expicitly set to "none". bz3567 Full release notes at https://www.openssh.com/txt/release-9.4 Relnotes: Yes Sponsored by: The FreeBSD Foundation 2022-04-13T20:00:56Z Ed Maste emaste@FreeBSD.org 2022-04-13T20:00:56Z urn:sha1:1323ec571215a77ddd21294f0871979d5ad6b992 Release notes are available at https://www.openssh.com/txt/release-8.9 Some highlights: * ssh(1), sshd(8), ssh-add(1), ssh-agent(1): add a system for restricting forwarding and use of keys added to ssh-agent(1) * ssh(1), sshd(8): add the sntrup761x25519-sha512@openssh.com hybrid ECDH/x25519 + Streamlined NTRU Prime post-quantum KEX to the default KEXAlgorithms list (after the ECDH methods but before the prime-group DH ones). The next release of OpenSSH is likely to make this key exchange the default method. * sshd(8), portable OpenSSH only: this release removes in-built support for MD5-hashed passwords. If you require these on your system then we recommend linking against libxcrypt or similar. Future deprecation notice ========================= A near-future release of OpenSSH will switch scp(1) from using the legacy scp/rcp protocol to using SFTP by default. Legacy scp/rcp performs wildcard expansion of remote filenames (e.g. "scp host:* .") through the remote shell. This has the side effect of requiring double quoting of shell meta-characters in file names included on scp(1) command-lines, otherwise they could be interpreted as shell commands on the remote side. MFC after: 1 month Relnotes: Yes Sponsored by: The FreeBSD Foundation 2021-09-08T01:05:51Z Ed Maste emaste@FreeBSD.org 2021-09-08T01:05:51Z urn:sha1:19261079b74319502c6ffa1249920079f0f69a72 Some notable changes, from upstream's release notes: - sshd(8): Remove support for obsolete "host/port" syntax. - ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". - ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm. - ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures. - ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). - ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions. - scp(1): this release changes the behaviour of remote to remote copies (e.g. "scp host-a:/path host-b:") to transfer through the local host by default. - scp(1): experimental support for transfers using the SFTP protocol as a replacement for the venerable SCP/RCP protocol that it has traditionally used. Additional integration work is needed to support FIDO/U2F in the base system. Deprecation Notice ------------------ OpenSSH will disable the ssh-rsa signature scheme by default in the next release. Reviewed by: imp MFC after: 1 month Relnotes: Yes Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D29985 2018-09-10T16:20:12Z Dag-Erling Smørgrav des@FreeBSD.org 2018-09-10T16:20:12Z urn:sha1:190cef3d52236565eb22e18b33e9e865ec634aa3 Approved by: re (kib@) 2018-05-08T23:13:11Z Dag-Erling Smørgrav des@FreeBSD.org 2018-05-08T23:13:11Z urn:sha1:4f52dfbb8d6c4d446500c5b097e3806ec219fbd4 This completely removes client-side support for the SSH 1 protocol, which was already disabled in 12 but is still enabled in 11. For that reason, we will not be able to merge 7.6p1 or newer back to 11. 2016-01-19T18:28:23Z Dag-Erling Smørgrav des@FreeBSD.org 2016-01-19T18:28:23Z urn:sha1:bc5531debefeb54993d01d4f3c8b33ccbe0b4d95 2016-01-19T16:18:26Z Dag-Erling Smørgrav des@FreeBSD.org 2016-01-19T16:18:26Z urn:sha1:a0ee8cc636cd5c2374ec44ca71226564ea0bca95 upstream) and a number of security fixes which we had already backported. MFC after: 1 week