Windows Server 2022

Winsage
May 26, 2026
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 15, 2026
Microsoft confirmed a BitLocker-related issue caused by the April 2026 Security Update (KB5083769) for Windows 11, which led some devices to boot into the BitLocker recovery screen. A fix has been released, but it is currently available only for Windows 11, version 25H2, with Windows 10 and Windows Server users awaiting a solution. Administrators are advised to remove the "Configure TPM platform validation profile for native UEFI firmware configurations" Group Policy setting before installing the April 2026 update. Additionally, a security researcher named Chaotic Eclipse has developed a zero-day exploit called YellowKey, which can bypass BitLocker security using a USB stick, affecting Windows Server 2022 and 2025 but not Windows 10.
Winsage
May 15, 2026
Windows systems are threatened by a vulnerability in the Windows DNS Client, identified as CVE-2026-41096, which allows remote code execution without user intervention. It has a CVSS base score of 9.8, indicating high severity. The flaw is a heap-based buffer overflow in the dnsapi.dll component, enabling unauthenticated remote attackers to execute arbitrary code. Exploitation requires sending a specially crafted DNS response to a vulnerable system, potentially leading to complete control over the host. Affected systems include supported versions of Windows 11 and Windows Server 2022/2025. Microsoft released security updates on May 12, 2026, and administrators are advised to apply these patches and reboot systems. Despite the severity, Microsoft currently classifies exploitation as “Exploitation Unlikely,” with no known public exploits or in-the-wild attacks.
Winsage
May 14, 2026
An anonymous cybersecurity researcher disclosed two new zero-day vulnerabilities affecting Microsoft systems: YellowKey and GreenPlasma. YellowKey is a BitLocker bypass that operates as a backdoor within the Windows Recovery Environment, impacting Windows 11 and Windows Server 2022/2025. Exploiting YellowKey involves copying specially crafted files to a USB drive, connecting it to a Windows computer, and rebooting into WinRE. The researcher expressed skepticism about Microsoft's response time to this vulnerability, noting that using TPM+PIN does not mitigate the risk. GreenPlasma is a privilege escalation vulnerability that allows an unprivileged user to obtain a shell with SYSTEM permissions through arbitrary section creation in Windows CTFMON. The proof-of-concept for this exploit is incomplete but indicates potential manipulation of trusted privileged services or drivers. Additionally, a related attack against BitLocker was detailed by French cybersecurity firm Intrinsec, which exploits a boot manager downgrade using CVE-2025-48804 to bypass encryption protections on fully patched Windows 11 systems. This method allows attackers to boot from a controlled WIM while the boot manager checks the legitimate one, executing with the decrypted BitLocker volume. Despite Microsoft releasing fixes for this defect in July 2025, a flaw in Secure Boot verification allows a vulnerable boot manager to bypass BitLocker safeguards. To mitigate these risks, enabling a BitLocker PIN at startup and migrating to a new boot manager certificate is recommended.
Winsage
May 13, 2026
A cybersecurity researcher known as Chaotic Eclipse has released proof-of-concept exploits for two unpatched vulnerabilities in Microsoft Windows: YellowKey, a BitLocker bypass, and GreenPlasma, a privilege-escalation flaw. The YellowKey vulnerability affects Windows 11 and Windows Server 2022/2025, allowing unauthorized access to BitLocker-protected volumes by exploiting the Windows Recovery Environment. The exploit can be executed using specially crafted 'FsTx' files on a USB drive or directly on the EFI partition. Independent researcher Kevin Beaumont has validated the exploit, which can bypass BitLocker protections even in a Trusted Platform Module (TPM) environment. The GreenPlasma vulnerability allows unprivileged users to create arbitrary memory-section objects, potentially leading to privilege escalation. Chaotic Eclipse has expressed dissatisfaction with Microsoft's handling of bug reports, prompting the public disclosure of these vulnerabilities. Microsoft has stated its commitment to investigating security issues and updating affected devices.
Winsage
April 20, 2026
Microsoft has released emergency updates for various versions of Windows Server due to issues arising from the April 2026 Patch Tuesday security updates. A significant problem was a reboot loop affecting domain controllers caused by crashes of the Local Security Authority Subsystem Service (LSASS), which disrupted authentication services. This issue was especially problematic during the setup of new domain controllers. Additionally, some Windows Server 2025 systems encountered difficulties in installing the security update KB5082063. The out-of-band update (KB5091157) for Windows Server 2025 addresses both the installation failure and the domain controller restart issue. Other updates targeting the domain controller restart problem were released for additional supported Windows Server versions. Microsoft has introduced an out-of-band update for seven versions, including KB5091157 for Windows Server 2025 and KB5091571 for Windows Server, version 23H2. Furthermore, some Windows Server 2025 devices may boot into BitLocker recovery mode after the update, requiring users to enter a BitLocker recovery key.
Winsage
April 20, 2026
Microsoft has confirmed that some administrators are experiencing difficulties installing the KB5082063 security update on Windows Server 2025. This month's Patch Tuesday updates have caused certain Windows servers, especially those with domain controller roles, to enter a restart loop due to failures in the Local Security Authority Subsystem Service (LSASS). Microsoft has released emergency out-of-band updates, including KB5091157 for Windows Server 2025, to address both the installation failure and the restart issues. Additionally, some Windows Server 2025 devices may boot into BitLocker recovery mode after installing the KB5082063 update. A bug affecting Windows Server 2019 and Windows Server 2022 that caused unexpected upgrades to Windows Server 2025 has also been resolved. Microsoft has issued various emergency updates throughout the year to address other issues, including a Bluetooth device visibility bug and vulnerabilities in the Routing and Remote Access Service (RRAS).
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