windows server
Microsoft: Domain Controller lookup may fail on Windows Server 2016
Microsoft has confirmed a new known issue affecting Windows Server 2016 systems that causes domain controller lookups to fail after installing the KB5087537 May 2026 security update. Windows Server 2016 reached the end of mainstream support in January 2022, but Microsoft has pushed back the extended support end date by 5 years to allow customers to […]
Microsoft shares mitigation for YellowKey Windows zero-day
Microsoft has shared mitigations for YellowKey, a recently disclosed Windows BitLocker zero-day vulnerability that grants access to protected drives. The security flaw was disclosed last week by an anonymous security researcher known as ‘Nightmare Eclipse,’ who described it as a backdoor and published a proof-of-concept (PoC) exploit. Nightmare Eclipse said that exploiting this zero-day involves placing specially […]
Microsoft confirms April Windows updates cause backup failures
Microsoft has confirmed that the April 2026 security updates are causing failures in third-party backup applications using the psmounterex.sys driver. As GeekFeed reported last week, this issue affects software using VSS (Volume Shadow Copy Service) snapshots and causes failures due to a VSS service timeout. Software impacted by this includes, but is not limited to, products from Macrium (Reflect), Acronis (Cyber […]
Microsoft: New Remote Desktop warnings may display incorrectly
Microsoft has confirmed a new issue causing newly introduced Windows security warnings to display incorrectly when opening Remote Desktop (.rdp) files. This known issue impacts all supported Windows versions, including Windows 11 (KB5083768 & KB5083769), Windows 10 (KB5082200), and Windows Server (KB5082063). As Microsoft explains in updates to the original advisories, “the security warning that appears […]
Microsoft releases emergency updates to fix Windows Server issues
Microsoft has released out-of-band (OOB) updates to fix issues affecting Windows Server systems after installing the April 2026 security updates. As Microsoft confirmed last week, some admins may experience failures when installing the KB5082063 security update on Windows Server 2025 devices. Additionally, this month’s Patch Tuesday cumulative updates are causing some Windows servers with domain controller […]
Microsoft: Some Windows servers enter reboot loops after April patches
Microsoft has confirmed that some Windows domain controllers are entering restart loops due to Local Security Authority Subsystem Service (LSASS) crashes after installing the April 2026 security updates. The company also warned that Windows admins may encounter this issue when setting up new domain controllers, or even on existing ones, if the server processes authentication […]
Recently leaked Windows zero-days now exploited in attacks
Threat actors are exploiting three recently disclosed Windows security vulnerabilities in attacks aimed at gaining SYSTEM or elevated administrator permissions. Since the start of the month, a security researcher known as “Chaotic Eclipse” or “Nightmare-Eclipse” has published proof-of-concept exploit code for all three security issues in protest to how Microsoft’s Security Response Center (MSRC) handled […]
New Microsoft Defender “RedSun” zero-day PoC grants SYSTEM privileges
A researcher known as “Chaotic Eclipse” has published a proof-of-concept exploit for a second Microsoft Defender zero-day, dubbed “RedSun,” in the past two weeks, protesting how the company works with cybersecurity researchers. This exploit is for a local privilege escalation (LPE) flaw that grants SYSTEM privileges in Windows 10, Windows 11, and Windows Server on […]
Microsoft: April Windows Server 2025 update may fail to install
Microsoft is investigating an issue causing this month’s KB5082063 security update to fail to install on some Windows Server 2025 systems. On affected systems, users are also reporting seeing 0x800F0983 install errors when trying to deploy the April 2026 cumulative updates. “Microsoft is monitoring diagnostic data reports on update installation failures and has observed a […]
Microsoft: April updates trigger BitLocker key prompts on some servers
Microsoft confirmed on Tuesday that some Windows Server 2025 devices will boot into BitLocker recovery after installing the April 2026 KB5082063 Windows security update. BitLocker is a Windows security feature that encrypts storage drives to prevent data theft. Windows computers typically enter BitLocker recovery mode after hardware changes or events such as TPM (Trusted Platform […]