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The fourth release candidate for Samba 4.18.0 has been released for testing.  Samba is the standard Windows interoperability suite of programs for Linux and Unix.

Samba 4.18.0rc4 Available for Download

This is the fourth release candidate of Samba 4.18.  This is *not* intended for production environments and is designed for testing purposes only.  Please report any defects via the Samba bug reporting system at

Samba 4.18 will be the next version of the Samba suite.




SMB Server performance improvements

The security improvements in recent releases
(4.13, 4.14, 4.15, 4.16), mainly as protection against symlink races, caused performance regressions for metadata heavy workloads.
While 4.17 already improved the situation quite a lot,
with 4.18 the locking overhead for contended path based operations is reduced by an additional factor of ~ 3 compared to 4.17. It means the throughput of open/close
operations reached the level of 4.12 again.

More succinct samba-tool error messages

Historically samba-tool has reported user error or misconfiguration by means of a Python traceback, showing you where in its code it noticed something was wrong, but not always exactly what is amiss. Now it tries harder to identify the true cause and restrict its output to describing that. Particular cases include:

 * a username or password is incorrect
 * an ldb database filename is wrong (including in smb.conf)  * samba-tool dns: various zones or records do not exist
 * samba-tool ntacl: certain files are missing
 * the network seems to be down
 * bad --realm or --debug arguments

Accessing the old samba-tool messages

This is not new, but users are reminded they can get the full Python stack trace, along with other noise, by using the argument '-d3'. This may be useful when searching the web.

The intention is that when samba-tool encounters an unrecognised problem (especially a bug), it will still output a Python traceback. If you encounter a problem that has been incorrectly identified by samba-tool, please report it on
Colour output with samba-tool --color

For some time a few samba-tool commands have had a --color=yes|no|auto option, which determines whether the command outputs ANSI colour codes. Now all samba-tool commands support this option, which now also accepts 'always' and 'force' for 'yes', 'never' and 'none' for 'no', and 'tty' and 'if-tty' for 'auto' (this more closely matches convention). With --color=auto, or when --color is omitted, colour codes are only used when output is directed to a terminal.

Most commands have very little colour in any case. For those that already used it, the defaults have changed slightly.

 * samba-tool drs showrepl: default is now 'auto', not 'no'
 * samba-tool visualize: the interactions between --color-scheme,    --color, and --output have changed slightly. When --color-scheme is    set it overrides --color for the purpose of the output diagram, but    not for other output like error messages.

New samba-tool dsacl subcommand for deleting ACES

The samba-tool dsacl tool can now delete entries in directory access control lists. The interface for 'samba-tool dsacl delete' is similar to that of 'samba-tool dsacl set', with the difference being that the ACEs described by the --sddl argument are deleted rather than added.
No colour with NO_COLOR environment variable

With both samba-tool --color=auto (see above) and some other places where we use ANSI colour codes, the NO_COLOR environment variable will disable colour output. See for a description of this variable. `samba-tool --color=always` will use colour regardless of NO_COLOR.

New wbinfo option --change-secret-at

The wbinfo command has a new option, --change-secret-at=domain controller which forces the trust account password to be changed at a specified domain controller. If the specified domain controller cannot be contacted the password change fails rather than trying other DCs.

New option to change the NT ACL default location

Usually the NT ACLs are stored in the security.NTACL extended attribute (xattr) of files and directories. The new
"acl_xattr:security_acl_name" option allows to redefine the default location. The default "security.NTACL" is a protected location, which means the content of the security.NTACL attribute is not accessible from normal users outside of Samba. When this option is set to use a user-defined value, e.g. user.NTACL then any user can potentially access and overwrite this information. The module prevents access to this xattr over SMB, but the xattr may still be accessed by other means (eg local access, SSH, NFS). This option must only be used when this consequence is clearly understood and when specific precautions are taken to avoid compromising the ACL content.

Azure Active Directory / Office365 synchronisation improvements --------------------------------------------------------------

Use of the Azure AD Connect cloud sync tool is now supported for password hash synchronisation, allowing Samba AD Domains to synchronise passwords with this popular cloud environment.


smb.conf changes

  Parameter Name                          Description     Default
  --------------                          -----------     -------

  acl_xattr:security_acl_name             New security.NTACL   server addresses                        New


o  Andreas Schneider
   * BUG 15308: Avoid that tests fail because other tests didn't do cleanup on

o  baixiangcpp
   * BUG 15311: fd_load() function implicitly closes the fd where it should not.


o  Jeremy Allison
   * BUG 15301: Improve file_modtime() and issues around smb3 unix test.
o  Ralph Boehme
   * BUG 15299: Spotlight doesn't work with latest macOS Ventura.
o  Stefan Metzmacher
   * BUG 15298: Build failure on solaris with tevent 0.14.0 (and ldb 2.7.0).
     (tevent 0.14.1 and ldb 2.7.1 are already released...)
o  John Mulligan
   * BUG 15307: vfs_ceph incorrectly uses fsp_get_io_fd() instead of      fsp_get_pathref_fd() in close and fstat.

o  Andreas Schneider
   * BUG 15291: doesn't work with
   * BUG 15301: Improve file_modtime() and issues around smb3 unix test.


o  Andrew Bartlett
   * BUG 10635: Office365 azure Password Sync not working.
o  Stefan Metzmacher
   * BUG 15286: auth3_generate_session_info_pac leaks wbcAuthUserInfo.
o  Noel Power
   * BUG 15293: With clustering enabled samba-bgqd can core dump due to use
     after free.


Reporting bugs & Development Discussion

Please discuss this release on the samba-technical mailing list or by joining the matrix room, or
#samba-technical IRC channel on

If you do report problems then please try to send high quality feedback. If you don't provide vital information to help us track down the problem then you will probably be ignored.  All bug reports should be filed under the Samba 4.1 and newer product in the project's Bugzilla database (

== Our Code, Our Bugs, Our Responsibility.
== The Samba Team


Download Details

The uncompressed tarballs and patch files have been signed
using GnuPG (ID AA99442FB680B620).  The source code can be downloaded from:

The release notes are available online at:
Our Code, Our Bugs, Our Responsibility.

                        The Samba Team