authentication issues Archives

Winsage

June 16, 2025

Windows Server update may disrupt IP refreshes

Microsoft has acknowledged that the June security update has caused complications for users of Windows Server systems, specifically affecting the Dynamic Host Configuration Protocol (DHCP) service, which is failing and leading to improper functioning of IP refreshes. The issue impacts multiple versions of Windows Server, including 2016 (KB5061010), 2019 (KB5060531), 2022 (KB5060526), and 2025 (KB5060842). Users have reported that the DHCP service may stop responding after installing the update, with one administrator noting their 2016 server crashed shortly after the update was applied. Microsoft is working on a solution and advises affected users to uninstall the update to restore functionality. The company has a history of DHCP-related issues dating back over a decade and has faced other problems with Windows Server updates in the past year, including issues with keyboard and mouse inputs and authentication challenges.

Winsage

June 16, 2025

Microsoft: June Windows Server security updates cause DHCP issues

Microsoft has identified an issue with the June 2025 security updates that causes the Dynamic Host Configuration Protocol (DHCP) service to freeze on certain Windows Server systems. This affects the service's ability to apply renewals of unicast IP addresses, impacting network operations. Microsoft has acknowledged that the DHCP Server service may intermittently stop responding after the update and is working on a resolution. Additionally, other issues affecting Windows Server systems have been addressed, including application failures and authentication problems on domain controllers. Out-of-band updates were previously issued to fix bugs causing Hyper-V virtual machines to restart or freeze, and emergency updates were released for issues with Windows containers on certain Windows Server versions.

Winsage

June 12, 2025

Microsoft Resolves Windows Server 2025 Restart Bug Disrupting Active Directory Connectivity

Microsoft released updates in June 2025 to address critical issues affecting Windows Server 2025 domain controllers, specifically authentication failures and network connectivity problems. The updates, encapsulated in KB5060842, resolved issues stemming from security update KB5055523, which altered certificate validation methods for Kerberos authentication. This change led to logging errors for self-signed certificates and affected Windows Hello for Business Key Trust deployments. Additionally, a separate issue prevented domain controllers from managing network traffic correctly after restarts, causing them to revert to standard firewall profiles. Microsoft provided a temporary workaround for administrators to manually restart network adapters until a permanent fix was implemented. The June updates addressed a total of 66 vulnerabilities, including 10 rated as Critical, and recommended immediate installation. Microsoft advised against setting the AllowNtAuthPolicyBypass registry key to ‘2’ for domain controllers using self-signed certificates until the latest updates were applied.

Winsage

June 11, 2025

Microsoft fixes Windows Server auth issues caused by April updates

Microsoft has resolved an authentication issue that arose after the April 2025 security updates on Windows Server domain controllers, primarily affecting Windows Server 2016, 2019, 2022, and 2025. The problem, acknowledged in early May, involved difficulties with Kerberos logons or delegations reliant on certificate-based credentials due to the April monthly security update (KB5055523). This issue could lead to authentication failures in environments using Windows Hello for Business Key Trust or Device Public Key Authentication, impacting various software solutions. Microsoft released cumulative updates to fix these issues and recommended installing the latest security updates. For those still facing problems, a temporary registry adjustment was advised. The authentication issues were linked to security enhancements addressing a high-severity vulnerability (CVE-2025-26647) that could allow privilege escalation through an input validation flaw in Windows Kerberos. Microsoft had previously addressed related authentication issues in April and issued emergency updates in November 2022 for Kerberos sign-in failures affecting Windows domain controllers.

Winsage

May 7, 2025

Microsoft: April updates cause Windows Server auth issues

Microsoft has acknowledged that the April 2025 security updates are causing authentication challenges for certain Windows Server domain controllers, specifically affecting Windows Server versions 2016, 2019, 2022, and 2025. The issues arise after installing the April Windows monthly security update (KB5055523 or later), leading to complications in processing Kerberos logons or delegations that rely on certificate-based credentials. Affected authentication protocols include Kerberos PKINIT, S4U via RBKCD, and KCD. These issues are linked to security measures addressing the critical vulnerability CVE-2025-26647, which allows authenticated attackers to escalate privileges remotely. A temporary workaround involves modifying a registry value. Microsoft has previously addressed similar authentication issues in Windows 11, Windows Server 2025, and earlier versions.

Winsage

April 23, 2025

Microsoft fixes Windows Server 2025 blue screen, install issues

Microsoft has addressed issues affecting Windows Server 2025 for systems with more than 256 logical processors, which could lead to installation failures, slow start-up times, and blue screen errors. These problems have been resolved through updates since the KB5046617 cumulative update released in November. IT administrators are advised to install the latest security updates, which include essential fixes. A temporary workaround involves limiting the number of logical processors to 256 or fewer by adjusting settings in the UEFI Setup. Additionally, Microsoft warned of potential accessibility issues with Windows Server 2025 domain controllers post-restart and reported login difficulties with Windows Hello after the April 2025 updates. A bug causing authentication issues with Credential Guard has been fixed, and a new safeguard hold for Windows 11 24H2 has been introduced due to compatibility problems with the SenseShield Technology's sprotect.sys driver.

Winsage

April 17, 2025

New Windows Server emergency updates fix container launch issue

Microsoft released emergency updates for Windows Server to address startup failures in containers operating under Hyper-V isolation mode, caused by compatibility issues with the 2025.04 B container images. The updates enhance access to essential system files from the Windows Server host, improving compatibility and reliability. These out-of-band updates for Windows Server 2019, 2022, and 2025 must be manually downloaded from the Microsoft Update Catalog, as they will not be delivered through Windows Update. This update follows previous challenges, including authentication issues and boot problems caused by earlier security updates for Windows Server 2019 and 2022.

Winsage

April 14, 2025

Microsoft: Windows Server 2025 restarts break connectivity on some DCs

Microsoft has warned IT administrators about a potential issue with Windows Server 2025 domain controllers (DCs) becoming inaccessible after a restart, due to defaulting to the standard firewall profile instead of domain-specific settings. This mismanagement can lead to DCs being unreachable on the domain network or improperly accessible through restricted ports and protocols. A workaround involves manually restarting the network adapter on affected servers after each reboot, and Microsoft recommends setting up a scheduled task for this. The company is working on a permanent solution for a future update. Additionally, Microsoft has alerted users to another issue with Windows Hello logins related to the KB5055523 April 2025 security update and has implemented a fix for authentication issues with Credential Guard and the Kerberos PKINIT pre-auth security protocol.

Winsage

April 9, 2025

Microsoft: April 2025 updates break Windows Hello on some PCs

Microsoft has announced that a subset of Windows users may have difficulties logging into their accounts via Windows Hello after installing the April 2025 security updates, specifically affecting Windows 11 24H2 and Windows Server 2025 with the KB5055523 update. The issue occurs on devices with Dynamic Root of Trust for Measurement (DRTM) or System Guard Secure Launch features enabled prior to the update. Users may see messages indicating problems with their PIN or facial recognition setup. Microsoft has provided workarounds for affected users, including re-enrollment in Windows Hello for both PIN and facial recognition. Additionally, Microsoft resolved another bug related to KB5055523 affecting Credential Guard and introduced a safeguard hold for Windows 11 24H2 systems using SenseShield Technology's sprotect.sys driver due to compatibility issues. Upgrade blocks have also been implemented for devices with incompatible software or hardware, including Dirac audio improvement software and certain applications.