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Patched SAMBA+ packages are now available to address the Netlogon protocol change introduced by Microsoft’s latest updates to Windows Active Directory Domain Controllers.

Following our initial announcement, the updates from Microsoft introduce a critical change that may impact Samba installations in certain configurations. To ensure compatibility, fixed SAMBA+ packages have been released for the following branches:

• SAMBA+ 4.21
• SAMBA+ 4.22

If you are still using an older release branch, we strongly recommend migrating to 4.21 or 4.22 to receive the necessary fix.

Who needs the update?
You only need to install the patched packages if:

• Samba is configured as a member server, and
• you're using the idmap backend ad

Other Samba setups are not affected.

For full technical details, please refer to the official Samba release notes:
Samba 4.21.7 Release Notes
Samba 4.22.3 Release Notes

If you need help updating your installation or have questions about compatibility, feel free to contact us – we’re happy to support you.

Debian 13 "Trixie" has not yet been officially released, but SAMBA+ packages are already available. Starting with version 4.22, SerNet provides prebuilt SAMBA+ packages for the upcoming Debian release. Supported architectures are amd64 and arm64, in line with Debian’s decision to discontinue 32-bit variants.

By offering early access to these packages, the SAMBA+ team ensures that administrators and IT professionals can plan and test ahead. This proactive approach supports smooth transitions and secure operations in demanding environments.

Built from the official Samba source code, SAMBA+ packages offer more than just compatibility. They include extended testing, continuous security updates and the option for enterprise-grade support directly from SerNet.

All supported platforms, including the new Trixie packages, are listed in our overview. Technical setup instructions and repository details are available in the How-to Section. 

For questions, feel free to contact us at sales@remove-this.sernet.com

(Last Update: July 8)

Please note: Updated packages are available

On July 8, Microsoft will release an important security update for Active Directory Domain Controllers for Windows Server versions prior to 2025.

This update modifies the Microsoft RPC Netlogon protocol to improve security by tightening access checks for a set of RPC requests. Samba running as domain members in these environments will be impacted by this change if a specific configuration is used. See below for details on the affected configurations.

Windows Server version 2025 is already equipped with these specific security hardenings. Microsoft plans to deploy them to all supported Windows Server versions down to Windows Server 2008. 

Who is affected?
Samba installations that act as member servers in Windows AD domains will be affected if they are configured to use the 'ad' idmapping backend. Samba servers that do not use this configuration will not be affected by the change – at least according to our current knowledge and understanding – and no further action is required.

However, current versions of Samba with the affected configuration will no longer function correctly once the Microsoft update has been applied. Users will not be able to connect to the SMB service provided by Samba for any domain that uses the ‘ad’ idmapping backend.

What is SerNet doing?
The SAMBA+ team at SerNet, along with other members of the international Samba team, has been collaborating with Microsoft. Changes to Samba are currently being developed and tested to ensure full compatibility between Samba and Microsoft products. The Samba team aims to release updated packages on Monday evening (UTC+2).

Updated SAMBA+ packages, which will restore full compatibility, are planned to be made available before Microsoft's rollout.

What you should do:

• Check your configuration if you’re running Samba in a Windows AD environment.
• Watch out for new SAMBA+ package updates early next week (starting July 7th) .
• Apply the update before Microsoft’s rolls out the patch.

All SAMBA+ updates are included in active subscriptions.

If you do not yet have a subscription, visit the SAMBA+ shop (EUR) or SAMBA+ shop (USD) for access.

For any questions or individual support, feel free to contact us directly – our team is here to help.

Following the official release of Red Hat Enterprise Linux (RHEL) 10 on May 20, 2025, the Samba team at SerNet swiftly released SAMBA+ 4.22 for RHEL 10. Subscribers can seamlessly access these latest packages.

Additionally, SAMBA+ 4.22 packages are immediately available for the following binary-compatible distributions:

• AlmaLinux 10
• CentOS Stream 10
• Oracle Linux 10
• Rocky Linux 10

SAMBA+ is particularly suitable for RHEL environments due to its optimized integration, robust performance, and consistent security updates. Built specifically with enterprise needs in mind, SAMBA+ ensures reliable interoperability between Linux/Unix servers and Windows-based clients. Moreover, regular, timely updates and comprehensive testing guarantee compatibility with RHEL's latest security enhancements and system improvements.

SAMBA+ 4.22 includes key enhancements such as SMB3 Directory Leases and SMB3 POSIX Extensions, further boosting performance, efficiency, and compatibility in enterprise scenarios.

For further details and to download your SAMBA+ packages, have a look at our version overview. More information and pricing can be found in the USD shop or the EUR shop. Existing subscriptions include access to the new packages.