Windows Server 2025 Archives

Winsage

June 18, 2026

Microsoft fixes Windows Server 2016 security update failures

Microsoft resolved an installation issue affecting the June 2026 security updates (KB5094122) on Windows Server 2016 systems that had not previously installed the KB5087537 update, which was a prerequisite. Users had encountered 0x80070002 or FILENOTFOUND errors. Microsoft acknowledged the problem and confirmed that affected devices should no longer experience installation failures for the June 2026 update. Additionally, Microsoft fixed a similar issue with the May 2026 Windows 11 security update (KB5089549) that resulted in 0x800f0922 errors due to insufficient space on the EFI System Partition. They also warned users about potential installation issues with error codes 0x80073712 or 0x800f0993 on devices upgraded to Windows 11 24H2 or 25H2. Furthermore, Microsoft addressed a boot issue for Windows Server 2025 devices after the April 2026 update and a bug affecting installation failures for updates since May 2025 using the Windows Update Standalone Installer (WUSA). Lastly, they are investigating a separate issue preventing third-party applications from launching essential Office programs after the June 2026 updates.

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June 13, 2026

Windows Server is getting new network safety capabilities with DNS over HTTPS

Microsoft has introduced DNS over HTTPS (DoH) on Windows Server 2025, enhancing network security by encrypting DNS traffic for client-to-server communications. This feature, previously available only in Windows client editions, is now part of Microsoft's Zero Trust architecture. DoH routes DNS traffic through HTTPS secured with TLS certificates, preventing eavesdropping and safeguarding DNS data from tampering. It adheres to the IETF DNS over HTTPS standard (RFC 8484) and can integrate with existing infrastructure, allowing organizations to maintain unencrypted DNS traffic if needed. DoH is available for Windows Server 2025 systems updated to the latest Patch Tuesday release, and Microsoft has provided guidance on enabling this feature. However, DNS traffic exchanged between two DNS servers will not be encrypted by DoH.

Winsage

June 13, 2026

Windows Server 2025 Adds DNS Over HTTPS for Secure DNS Traffic

Microsoft has rolled out support for DNS over HTTPS (DoH) in Windows DNS Server as part of the Windows Server 2025 update. This feature enhances the security of DNS communications through encryption and server authentication, allowing encrypted client-to-resolver traffic in on-premises DNS environments. DoH encrypts DNS queries and responses using HTTPS, protecting sensitive information from interception or alteration. It also uses digital certificates for DNS server authentication to reduce spoofing and impersonation risks. The feature is compatible with existing Windows DNS Server configurations and supports both encrypted and traditional DNS. DoH support is available on Windows Server 2025 with the June 9, 2026 update or newer. Administrators must configure a trusted TLS certificate and enable DoH in the DNS Server service to deploy this feature. Microsoft plans to extend encryption capabilities to include communication between the Windows DNS Server and upstream DNS resolvers in the future.

Winsage

June 12, 2026

Microsoft fixes Windows update failures linked to WUSA installer

Microsoft resolved an issue affecting the installation of Windows updates released since May 2025, which primarily impacted users using the Windows Update Standalone Installer (WUSA) from a network share, especially in enterprise environments. The problem was significant for devices running Windows 11 24H2/25H2 and Windows Server 2025, but did not occur when handling a single .msu file or when files were stored locally. In August 2025, Microsoft acknowledged that updates installed using WUSA might fail with error ERRORBADPATHNAME when multiple .msu files were involved. A Known Issue Rollback Group Policy was implemented in September 2025 to mitigate the impact on home and non-managed business devices. The issue was ultimately resolved with cumulative updates released in June 2026 for Windows 11 (KB5079391) and Windows Server 2025 (KB5094125). Microsoft provided a workaround for users experiencing difficulties with prior updates by suggesting they save .msu files locally for installation. Users were also advised to wait at least 15 minutes after installing an .msu file via WUSA before checking the Update History page. Additionally, Microsoft had previously addressed another issue in April 2025 that affected enterprise customers installing security updates via WSUS, which recurred in the August 2025 updates. Microsoft warned customers about potential issues with installing the latest monthly updates on devices upgraded to Windows 11 24H2 or 25H2.

Winsage

June 11, 2026

Microsoft fixes BitLocker recovery bug on Windows Server 2025

Microsoft has resolved an issue affecting certain Windows Server 2025 devices that were booting into BitLocker recovery mode after the April 2026 security update. This issue was linked to specific BitLocker Group Policy configurations and required users to input their BitLocker recovery key upon the first restart after the update. However, this key would only need to be entered once for subsequent restarts, provided the group policy configuration remained unchanged. The problem primarily affected enterprise systems rather than personal devices. The issue arose under specific conditions: BitLocker was enabled on the operating system drive, a particular Group Policy was set, the Secure Boot State PCR7 Binding was "Not Possible," the Windows UEFI CA 2023 certificate was present, and the device was not already using the 2023-signed Windows Boot Manager. Microsoft released fixes in the KB5094125 and KB5093998 updates to address this problem, preventing devices with incompatible group policy configurations from installing the 2023-signed Windows Boot Manager. Event ID 1032 in the System event log indicates the issue when Windows updates are installed. For IT administrators unable to deploy the latest updates, it is recommended to remove the Group Policy configuration before installing updates or to implement a Known Issue Rollback (KIR) on affected devices. Additionally, Microsoft had previously addressed similar BitLocker recovery issues in August 2024 and May 2025.

Winsage

June 10, 2026

Windows BitLocker 0-Day Vulnerability Allows Attackers to Bypass Security Feature

On June 9, 2026, Microsoft announced a vulnerability in Windows BitLocker, identified as CVE-2026-50507, which allows unauthorized attackers with physical access to bypass BitLocker Device Encryption. The flaw is categorized under CWE‑306, indicating a missing authentication check for a critical function, and has a CVSS v3.1 base score of 6.8. It affects various versions of Windows 10, Windows 11, and Windows Server from 2012 R2 to 2025. Microsoft released security updates to address the vulnerability, and it was classified as “Exploitation More Likely.” Although there is no evidence of active exploitation, proof-of-concept code exists. Organizations are advised to implement multi-factor configurations and reassess device handling and security protocols.

Winsage

May 28, 2026

Windows Server 2016 fails to find domain controller

Microsoft has acknowledged an issue with the May 2026 security update for Windows Server 2016, affecting systems with hostnames of exactly 15 characters, which leads to failed domain controller (DC) lookups. The error occurs during DC lookups, specifically returning the error code ERRORINVALIDPARAMETER. Servers with 14 or 16 character hostnames are not affected. Administrators may face challenges with DFS Namespace management and other functions reliant on DC access. Microsoft is investigating the issue but has not provided a timeline for a fix. Windows Server 2016's mainstream support ended in January 2022, but extended support will continue until January 2027.

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May 26, 2026

Microsoft: Domain Controller lookup may fail on Windows Server 2016

Microsoft has acknowledged an issue affecting Windows Server 2016 systems related to domain controller lookups after the installation of the KB5087537 security update released in May 2026. The problem occurs specifically for devices with hostnames that are exactly 15 characters long, causing domain controller discovery to fail and resulting in an ERRORINVALIDPARAMETER during DCLocator calls. This issue may disrupt administrative operations that depend on domain controller lookups, such as DFS Namespace management. Microsoft is investigating the issue but has not provided a timeline for resolution.

Winsage

May 25, 2026

Windows zero-days expose gaps in built-in security protections

Two Windows zero-day vulnerabilities, YellowKey and GreenPlasma, have been identified. YellowKey targets the Windows Recovery Environment (WinRE) on Windows 11 and Windows Server 2025, allowing attackers with physical access to bypass BitLocker protections using a USB device. GreenPlasma affects Windows 10, Windows 11, and Windows Server environments with active Collaborative Translation Framework Monitor (CTFMON) sessions, enabling local privilege escalation from a standard user account to SYSTEM-level privileges. Both vulnerabilities require either physical or local access to exploit. Microsoft has not yet released patches for these vulnerabilities, prompting organizations to enhance their security measures and operational resilience. Recommendations include reassessing physical security, limiting local administrative access, and implementing multifactor authentication and robust credential management practices.

Winsage

May 23, 2026

CVE-2026-45585: YellowKey BitLocker Bypass

BitLocker, a security feature for data protection, has a vulnerability identified as CVE-2026-45585, also known as YellowKey, which allows unauthorized access to encrypted data on Windows 11 versions 24H2, 25H2, 26H1, and Windows Server 2025. This flaw does not compromise BitLocker’s encryption but affects the recovery environment supporting it. The vulnerability can be exploited locally through the Windows Recovery Environment (WinRE) by an attacker with physical access, who can trigger an unrestricted shell and access the BitLocker-protected volume. Microsoft has provided two mitigation strategies: modifying the WinRE image to remove the autofstx.exe entry and transitioning from TPM-only protection to a TPM+PIN requirement at startup. The exploit poses challenges for detection, as it occurs pre-boot and currently lacks vendor-published indicators of compromise. Organizations using BitLocker for unattended devices are particularly at risk, as the vulnerability can lead to loss of confidentiality if an attacker gains access before the legitimate user.