Public bug reported:
A new release of openssh is available for merging from Debian.
Ubuntu Proposed: 1:10.5p1-1ubuntu3
Debian Unstable: 1:10.6p1-1
### New Debian Changes ###
openssh (1:10.6p1-1) unstable; urgency=medium
* New upstream release:
- scp(1): begin deprecating the -R flag, which is used to perform a
remote-to-remote copy by executing scp on a remote host. This option
is a fragile optimisation that is difficult to use because it requires
credentials on the remote host. It also creates security risks if the
shell quoting rules on the remote system where the copy is performed
differ from the client's expectations.
From OpenSSH 10.6, this option will continue to work but will cause a
deprecation warning to be emitted to standard error. In a future
release, the option will be ignored and will leave in place the
default remote-to-remote copy behaviour (copy via the host running
scp).
- SECURITY: sftp(1): more strictly validate paths returned from the
server to avoid some cases where a server could return paths that
could manipulate a recursive copy operation into writing outside its
target directory.
- SECURITY: sshd(8): when GSSAPIAuthentication is in use, only store
GSSAPI credentials when authentication has succeeded. Avoids a
situation where credentials from a failed GSSAPIAuthentication attempt
may persist and be made inappropriately available if another
authentication subsequently succeeds.
- SECURITY: sshd(8): reset GSSAPIAuthentication before authentication,
avoiding state from one authentication attempt being confused with
that of a later attempt.
- SECURITY: sshd(8), ssh(1): disable LZ77 dictionary coder to mitigate
side-channel leaks. A chosen-plaintext attack method exists which
makes use of dictionary-based compression to recover secrets from one
channel by interacting with the SSH session's shared compression
dictionary through another channel.
Attacker-controlled input can recognizably reflect into the total
length of transmitted ciphertexts by virtue of LZ77 replacing repeated
strings with back-references into the SSH session's encoder search
buffer, which is shared across all channels. For this reason, the
documentation already recommended against enabling compression for
connections that share trusted and untrusted traffic.
This change will reduce the effectiveness of the Compression option.
Users are encouraged to use application-level compression over the SSH
protocol where possible, as this will typically be more effective and
will be completely immune to this type of attack.
- SECURITY: ssh(1): disallow '$' and '\' characters in usernames entered
on the command-line to avoid usernames from untrusted sources yielding
injection in shell context via ProxyCommand, Match exec, etc.
Usernames specified via the configuration files are not subject to
this control.
We continue to recommend against directly exposing ssh(1) and other
tools' command-lines to untrusted input. Mitigations such as this
cannot be absolute given the variety of shells and user configurations
in use.
- SECURITY: ssh-keygen(1): correct handling of Daylight Saving Time when
converting dates. Previous handling could cause errors of up to +/- 1
hour (unless you are in the Antarctica/Troll timezone, where the error
could be +/- 2 hours). These errors could result in creation of
certificates with incorrect expiry times.
- SECURITY: sshd(8), ssh(1): ensure that compressed payloads don't
inflate past the maximum supported packet length.
- SECURITY: sshd(8): fully honor the authorized_keys "restrict" keyword,
which was not being properly applied to tunnel forwarding
(PermitTunnel, disabled by default).
- SECURITY: sshd(8): correctly handle some options that accept "none".
Some options, including AuthorizedPrincipalsFile, were documented as
accepting "none" as a way to disable them; however, when overridden by
an sshd_config(5) Match keyword, this argument was being incorrectly
interpreted as a literal file.
- All: enable hybrid post-quantum ssh-mldsa44-ed25519 signature
algorithm. Note that this no longer uses the "@openssh.com" vendor
extension suffix that the previous experimental implementation used.
Keys generated with the previous experimental support must be
regenerated and/or removed.
- sshd(8): Add the WarnWeakCrypto option to sshd_config(5). This option
was previously available for the client only. This option is enabled
by default and will log when the client uses a key agreement scheme
that is not post-quantum safe.
- ssh-keygen(1), ssh-add(1): preserve user-verification (PIN or
biometric) requirement for resident keys loaded from a FIDO token, by
checking the credential's credProtect policy.
- ssh(1): include local and remote version strings in the ~I connection
information display.
- ssh-add(1): add a -P flag to skip PIN entry for FIDO and PKCS#11
tokens that do not require it.
- sftp(1): add '-p' flag for mkdir/lmkdir to create directories as
required. This flag has similar ergonomics to mkdir(1), and
previously-existing directories do not cause an error.
- ssh-keygen(1): add a "hexdump" key export mode that dumps the SSH
wire-formatted key blob in hex format. Useful when writing
documentation, tests, etc. E.g. `ssh-keygen -em hexdump -f /key`.
- ssh(1), sshd(8): ChannelTimeout now accepts timeouts with fractional
seconds.
- sshd(8): allow specification of the location of $SSH_AUTH_SOCK used
for agent forwarding using a new AgentSocketPath option. This supports
both using a user-specific path, such as the default of a subdirectory
of $HOME ("user:.ssh/agent"), and the previous approach of allowing
agent forwarding sockets to be located in a shared directory (e.g.
"shared:/tmp"). Sockets created in shared directories will be created
inside a subdirectory with a randomised name.
- ssh-agent(1): allow specification of agent socket directories using a
-A flag. It accepts "user:" and "shared:" directory styles similar to
the sshd AgentSocketPath option.
- sshd(8): account for public key authentication "key ok" tests
separately to auth attempts. Add a `PubkeyOptions max-pk-ok:nnnn`
option to allow a number of PK_OK tests (asking whether the server
might accept a given public key) that do not count against
MaxAuthTries, defaulting to 6 attempts. After these attempts are
exhausted, further attempts count as failed authentications against
MaxAuthTries. Practically, this allows more keys on disk or held in
ssh-agent to be checked for use before the server disconnects.
- ssh(1), sshd(8): extend the existing TCPKeepAlive option to also
support setting keepalives on sockets created for forwarding
connections. Previously this option controlled keepalives on the
connection socket only. TCPKeepAlive "yes" or "transport" enables
keepalives on the connection socket. "TCPKeepAlive all" additionally
enables them for forwarding sockets.
- sshd(8), ssh(1): fix configuration matching on more Turkic languages
which have disjoint dotted and dotless i/I characters, specifically
Azerbaijani and Crimean Tatar.
- ssh(1), sshd(8): don't attempt to set TCP_NODELAY on non-IP/IPv6
sockets. Eliminates some noise in debug logs.
- ssh(1): fix case for ssh -G option output.
- ssh(1), sshd(8): Fix ChannelTimeout specificity; previously a more
specific channel type (e.g. "session:shell") could clobber a
user-specified ChannelTimeout if it was less specific (e.g.
"session"). Also, in some cases, the debug messages were printing 0
instead of the effective timeout.
- sftp(1): avoid NULL dereference crash in some circumstances when a
server fails a stat/lstat operation.
- sshd(8): close a race condition where a SIGTERM/SIGQUIT would be
ignored if it was received by the server while it was processing a
SIGHUP restart request.
- sshd(8), ssh(1): check key and CA signature types during key parsing
against allowlists (PubkeyAcceptedAlgorithms, etc) as early as
possible. This reduces the attack surface presented by disabled
algorithms.
- All: switch the fallback implementation of the ed25519 signature
algorithm used when libcrypto is disabled from SUPERCOP ed25519 to
libsodium. The libsodium implementation includes a number of
strictness checks over the original reference implementation we have
used to this point and a more ergonomic API.
- ssh-add(1), ssh(1), ssh-keygen(1): fix spin on password entry when the
program attempting to read a password was started in a background
process group, with no TTY and with certain signals ignored.
- scp(1): disallow nul byte in received scp -O filename. This was not
reachable in normal operation.
- ssh-keygen(1), ssh(1), sshd(8): implement a maximum number of KDF
rounds that will be accepted when writing an OpenSSH-format private
key or when loading one. This limit is set quite high (1M), but
ensures that a service that is passed a bad key with a ridiculously
high number of rounds will eventually complete parsing it.
- ssh-keygen(1): bump the default number of KDF rounds from 24 to 32
(this is a linear increase, not like bcrypt(3) which is exponential).
- ssh(1): make StreamLocalBindMask properly respect Host/Match blocks
and make it first-match-wins as documented.
- sshd(8): make StreamLocalBindMask properly first-match-wins.
- sshd(8): don't link sshd against libselinux when SELinux support is
enabled (note: this library is still linked for the sshd-auth and
sshd-session helper binaries).
- sshd(8): restrict mremap(2) flags accepted by the seccomp sandbox.
Only MREMAP_MAYMOVE is now accepted as other flags may have some
utility in attack chains.
- sshd(8): allow PAMServiceName in Match (regressed in 10.4). During the
refactor of server option parsing, the ability to set PAMServiceName
in Match blocks was accidentally disabled.
* Generate MLDSA44-ED25519 host key by default (closes: #1142934).
* Remove Lintian overrides that now only apply to openssh-gssapi.
* Remove copyright entry that now only applies to openssh-gssapi.
* Skip purging if openssh-{client,server}-gssapi is installed (closes:
#1148080).
-- Colin Watson <[email protected]> Tue, 06 Oct 2026 18:00:40 +0100
### Old Ubuntu Delta ###
openssh (1:10.5p1-1ubuntu3) stonking; urgency=medium
[ Colin Watson ]
* d/openssh-{server,client}.postrm: Skip purging if
openssh-{client,server}-gssapi is installed
(Closes: #1148080 LP: #2169738)
* d/t/control, d/t/purge-keeps-config-with-counterpart: test to validate
that switching to the openssh counterparts and then purging the
removed packages keeps the configuration intact
-- Andreas Hasenack <[email protected]> Tue, 06 Oct 2026
15:04:38 -0300
openssh (1:10.5p1-1ubuntu2) stonking; urgency=medium
* d/p/lp-2150273-openssh-pam-upn: Fix PAM user mismatch with
alternative UPN suffixes by comparing account UIDs instead of
username strings (LP: #2150273)
* d/t/password-auth-no-pam: create /run/sshd for the custom test
service (LP: #2166924)
-- Finn Rayk Gartner <[email protected]> Wed, 09 Sep 2026
21:08:58 +0200
openssh (1:10.5p1-1ubuntu1) stonking; urgency=medium
* Merge with Debian unstable (LP: #2166081). Remaining changes:
- debian/rules: modify dh_installsystemd invocations for
socket-activated sshd
- debian/README.Debian: document systemd socket activation.
- debian/.gitignore: drop file
- debian/openssh-server.ucf-md5sum: update for Ubuntu delta
- d/p/systemd-socket-activation.patch:
+ Fix sshd re-execution behavior when socket activation is used
+ Adapt sshd-session and sshd-auth for systemd socket activation
+ Allow AF_VSOCK sockets
- debian/tests/systemd-socket-activation: Add autopkgtest for systemd socket
activation functionality.
- debian/patches: Immediately report interactive instructions to PAM clients
- debian/control: Build-Depends: systemd-dev
- d/p/sshd-socket-generator.patch: add generator for socket activation
- debian/openssh-server.install: install sshd-socket-generator
- debian/openssh-server.postinst: restart whichever systemd unit is enabled
- d/t/sshd-socket-generator: add dep8 test for sshd-socket-generator
- ssh.socket: adjust unit for socket activation by default
- debian/rules: explicitly enable LTO
- d/p/test-set-UsePAM-no-on-some-tests.patch: set UsePAM=no for some tests
- d/openssh-server.links: add full sshd.service -> ssh.service alias
(LP #2087949)
- document /etc/ssh/sshd_config.d/*.conf better in sshd_config
(LP #2088207)
- d/rules,d/control: do not build with wtmpdb support
- d/t/control: add breaks-testbed restriction to tests
- d/tests: do not fail when $HOME/.ssh exists
- test: workaround test failure caused by uutils dd (LP #2125943)
- d/rules: only act on files from bin:openssh-tests if it's being
built (LP #2165026)
- d/t/control: disable regress test on i386, since bin:openssh-tests
is not built for that architecture in Ubuntu
* Dropped:
- d/t/password-auth-no-pam: create the privilege separation
directory manually for this test, as it doesn't use the systemd
service unit to start sshd
[Not needed since 1:10.5p1-1]
-- Andreas Hasenack <[email protected]> Tue, 01 Sep 2026
14:45:43 -0300
** Affects: openssh (Ubuntu)
Importance: Wishlist
Status: New
** Tags: needs-merge upgrade-software-version
** Changed in: openssh (Ubuntu)
Importance: Undecided => Wishlist
** Changed in: openssh (Ubuntu)
Milestone: None => ubuntu-26.11
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https://bugs.launchpad.net/bugs/2171147
Title:
Merge openssh 1:10.6p1-1 from Debian for tenacious cycle
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