Announce: OpenSSH 10.5 released

Tue Aug 11 14:40:18 AEST 2026

OpenSSH 10.5 has just been released. It will be available from the
mirrors listed at https://www.openssh.com/ shortly.

OpenSSH is a 100% complete SSH protocol 2.0 implementation and
includes sftp client and server support.

Recently the OpenSSH team have received a large number of security
bug reports, many of which are findings from AI models or made with
AI assistance. While many AI reports are determined not to have
security impact when considered in the context of a realistic
threat model, we very much welcome these reports, especially when
combined with human triage, analysis, test-cases and particularly
when accompanied by proposed fixes.

We have seen a number of cases where a security bug identified by
AI tools is subsequently independently discovered by a different
researcher. This suggests that adversaries who do not report bugs
to OSS projects are likely to be able to discover these bugs too.
Given this, the OpenSSH team will, for now, be making more frequent
releases to get bugfixes into users' hands more quickly rather than
batching them until the next planned release.

Once again, we would like to thank the OpenSSH community for their
continued support of the project, especially those who contributed
code or patches, reported bugs, tested snapshots or donated to the
project. More information on donations may be found at:
https://www.openssh.com/donations.html

Potentially-incompatible changes
--------------------------------

 * Portable OpenSSH now requires ECC (Elliptic Curve Cryptography)
   support in libcrypto, including support for the NISTP521 curve.
   ECC is included in the default build configurations of all
   versions of all libcrypto implementations currently supported by
   OpenSSH, including LibreSSL, OpenSSL, BoringSSL and AWS LC.
   The --without-openssl build configuration is not affected.

Changes since OpenSSH 10.4
==========================

This release contains a number of security fixes and small bugfixes.

Security
========

 * ssh-agent(1): fix an interaction between agent locking and the
   session-bind at openssh.com extension that is used to identify
   forwarded agents. These binding requests were refused when the
   agent was locked, with the result that operations that were
   intended to be limited to local use only could be performed
   remotely, including the ability to add PKCS#11 tokens and make
   use of keys that had destination restrictions applied.
   Reported by sn0x-sharma

 * ssh(1): avoid potential realloc use-after-free in the client if a
   remote forwarding is added via the local session multiplexing
   socket while a remote forwarding open request is pending with the
   server. Report and fix from Brian Mingus of Cognatory

 * sshd(8): make the authorized_keys "restrict" keyword apply
   correctly to tunnel forwarding too (which is administratively
   disabled by default). Reported by Erichen, Institute of Computing
   Technology, Chinese Academy of Sciences

New features
------------

 * ssh-keygen(1): add ability to set or clear the touch-required and
   verify-required flags on FIDO private keys when resetting a
   private key's passphrase.

 * ssh(1): tweak ordering of certificates tried during pubkey
    authentication to prefer FIDO keys that do not require user
    presence (touch) first, and FIDO keys that require user
    verification via PIN or biometrics last. This effectively tries
    low-friction authenticators before higher friction ones.

 * ssh(1): add a "ssh -Z user at host" mode that prints the keys that
   will be tried for public key authentication in the order that
   they will be used.

 * sshd(8) use setproctitle(3) to identify sshd-session when its
   acting as a post-authentication monitor.

Bugfixes
--------

 * ssh-keyscan(1): make reading the server banner a non-blocking
   operation to prevent a stuck server from blocking a many-host
   keyscan from proceeding.

 * sshd(8): use sshpkt_fatal() instead of plain fatal() for errors
   in the packet code as this provides context of the failing peer
   (address, port, user, etc).

 * sshd(8): when signing hostkey proofs for a client UpdateHostKeys
   request, allow each hostkey to perform at most one signature
   operation.

 * sshd(8) fix GSSAPI option names, that were broken during a
   servconf.c refactoring in openssh-10.4; bz3974.

 * ssh-keygen(1): pass back errors from ed25519 key generation, which
   theoretically can fail. GHPR702.

 * sshd(8): move check of public key type against allowed algorithms
   to before parsing of the key sent by the peer. This removes at
   least some key parsing and verification paths from the pre-auth
   attack surface. Suggested by Christopher Paul Rohlf of Anthropic.

 * ssh-keygen(1): fix double frees (impossible to reach outside of a
   test harness), and also use freezero where possible. From
   Christopher Paul Rohlf at Anthropic.

 * sshd(8): fix ChannelTimeout and RekeyLimit not being applied in
   sshd_config Match blocks.

 * sshd(8): in sshd config dump mode, write all directives in mixed
   case for consistency

Portability
-----------

 * sshd(8): re-allow PAMServiceName inside a Match block, which
   was incorrectly disabled during a refactoring in openssh-10.4.
   bz3987

Checksums:
==========

 - SHA1 (openssh-10.5.tar.gz) = 273163972f623bb9bffef9fd75a85c74d3b22633
 - SHA256 (openssh-10.5.tar.gz) = 9Zhp0C/mDWNLmnatq68mtbqOUhvbyYcffH04dsHUwZQ=

 - SHA1 (openssh-10.5p1.tar.gz) = 3067e2af7c526b31c7e94bc3ed38904ef791eb2c
 - SHA256 (openssh-10.5p1.tar.gz) = 1E0oqDnqna+WnMaRUP3lmRCys5Nh2tgaO9bL0ZIY2xE=

Please note that the SHA256 signatures are base64 encoded and not
hexadecimal (which is the default for most checksum tools). The PGP
key used to sign the releases is available from the mirror sites:
https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc

Reporting Bugs:
===============

- Please read https://www.openssh.com/report.html
  Security bugs should be reported directly to openssh at openssh.com