Microsoft Windows 11 April 2026 Security Update Breaks Third-Party Backup Applications
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Microsoft\u2019s April 2026 cumulative security update for Windows 11 is causing significant disruptions for users relying on third-party backup software, triggering an MS-DEFCON level 3 advisory from security patch analyst Susan Bradley at AskWoody.<\/p>\n
The problematic update, KB5083769<\/a>, applies to Windows 11 versions 24H2 and 25H2 (OS Builds 26200.8246 and 26100.8246), released on April 14, 2026.<\/p>\n At the root of the issue is a malfunction in Microsoft\u2019s Volume Shadow Copy Service (VSS) a critical Windows component that enables snapshot-based backup and restore operations across a wide range of enterprise and consumer backup solutions.<\/p>\n When VSS fails, backup jobs either stall or terminate with timeout errors, leaving systems without scheduled backup coverage a serious risk for both individual users and enterprise environments.<\/p>\n Multiple third-party vendors have already acknowledged the problem:<\/p>\n It is important to note that not all backup solutions are affected. Microsoft\u2019s native Windows 11 cloud-based Backup feature does not rely on VSS and remains unaffected.<\/p>\n The VSS component is also foundational to Microsoft\u2019s forthcoming Point-in-Time Restore (PITR) feature for Windows 11, first previewed during Microsoft Ignite in November 2025 via Insider build KB5070307<\/a>.<\/p>\n Since PITR has not yet reached general availability, most standard users face no additional risk from that front.<\/p>\n For users experiencing backup failures after installing KB5083769, the following rollback procedure is advised:<\/p>\n Before uninstalling, verify whether your specific backup solution is impacted by checking your vendor\u2019s official support channels and forums.<\/p>\n MS-DEFCON 3 signals that administrators should hold off on deploying KB5083769 in production environments until Microsoft issues a fix, Susan Bradley at AskWoody said<\/a>.<\/p>\n A patch addressing the VSS regression is anticipated in an upcoming out-of-band or May 2026 cumulative update.<\/p>\n Follow us on Google News<\/a>, LinkedIn<\/a>, and X<\/a> for daily cybersecurity updates. Contact us<\/a> to feature your stories.<\/strong><\/p>\n The post Microsoft Windows 11 April 2026 Security Update Breaks Third-Party Backup Applications<\/a> appeared first on Cyber Security News<\/a>.<\/p>\n<\/div>\nAffected Vendors<\/strong><\/h2>\n
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