Microsoft CVD response for Windows Defender and BitLocker
Advisory/Mitigation
Summary
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Microsoft is urging Coordinated Vulnerability Disclosure (CVD) and says it is developing security updates for Windows components including Defender and BitLocker after multiple zero-days were publicly disclosed. The response is aimed at reducing unnecessary risk for customers while Microsoft assesses impact and hardens affected systems. The company warned that releasing proof-of-concept details for unpatched vulnerabilities can create real-world consequences. The advisory posture is tied to active mitigation work and vendor coordination around the disclosed flaws.
Related Happenings
Microsoft SharePoint remote code execution (CVE-2026-45659)
Vulnerability
First: 26.05.2026 14:49
Last: 26.05.2026 14:49
Sources 1
About this happening:
**Microsoft SharePoint** **CVE-2026-45659** is a **remote code execution** vulnerability that lets an **authenticated attacker** with **Site Member** permissions run code over the...
Microsoft SharePoint remote code execution (CVE-2026-45659)
VulnerabilityAbout this happening: **Microsoft SharePoint** **CVE-2026-45659** is a **remote code execution** vulnerability that lets an **authenticated attacker** with **Site Member** permissions run code over the...
Microsoft security patch release for CVE-2026-45659
Security Patch Release
First: 26.05.2026 14:49
Last: 26.05.2026 14:49
Sources 1
About this happening:
Microsoft released **SharePoint** updates for **CVE-2026-45659**, a **remote code execution** flaw that could let an authenticated attacker run code over the network without eleva...
Microsoft security patch release for CVE-2026-45659
Security Patch ReleaseAbout this happening: Microsoft released **SharePoint** updates for **CVE-2026-45659**, a **remote code execution** flaw that could let an authenticated attacker run code over the network without eleva...
Microsoft Defender zero-days exploited in attacks (multiple vulnerabilities)
Vulnerability
First: 21.05.2026 10:49
Last: 21.05.2026 10:49
Sources 1
How related:
Following disclosure, BlueHammer, RedSun, and UnDefend have all come under active exploitation in the wild.
About this happening:
Microsoft began rolling out fixes for **CVE-2026-41091** and **CVE-2026-45498**, two **actively exploited zero-days** in **Microsoft Defender** components that affect unpatched Wi...
Microsoft Defender zero-days exploited in attacks (multiple vulnerabilities)
VulnerabilityHow related: Following disclosure, BlueHammer, RedSun, and UnDefend have all come under active exploitation in the wild.
About this happening: Microsoft began rolling out fixes for **CVE-2026-41091** and **CVE-2026-45498**, two **actively exploited zero-days** in **Microsoft Defender** components that affect unpatched Wi...
Microsoft security patch release for CVE-2026-41091 and CVE-2026-45498
Security Patch Release
First: 21.05.2026 10:49
Last: 21.05.2026 10:49
Sources 1
About this happening:
Microsoft rolled out security updates for Defender and related malware protection components to address two zero-days: CVE-2026-41091 and CVE-2026-45498. The fixes cover affected...
Microsoft security patch release for CVE-2026-41091 and CVE-2026-45498
Security Patch ReleaseAbout this happening: Microsoft rolled out security updates for Defender and related malware protection components to address two zero-days: CVE-2026-41091 and CVE-2026-45498. The fixes cover affected...
Latest development: 21.05.2026 12:52
Microsoft released patches for Microsoft Defender Antimalware Platform version 4.18.26040.7 to address CVE-2026-41091, a link-following privilege-escalation flaw that can let an authorized attacker elevate privileges locally to System, and CVE-2026-45498, a denial-of-service flaw. Microsoft said both vulnerabilities were publicly disclosed and exploited in the wild as zero-days. CISA added both flaws to its Known Exploited Vulnerabilities (KEV) list and urged federal agencies to patch them by June 3.
Rising critical Microsoft vulnerabilities across Windows, Azure, Dynamics 365, and Office
Target Trend
First: 19.05.2026 17:00
Last: 19.05.2026 17:00
Sources 1
About this happening:
Microsoft’s vulnerability volume stayed broadly stable, but **critical flaws** doubled year over year across **Windows, Azure, Dynamics 365, and Office**, increasing the likelihoo...
Rising critical Microsoft vulnerabilities across Windows, Azure, Dynamics 365, and Office
Target TrendAbout this happening: Microsoft’s vulnerability volume stayed broadly stable, but **critical flaws** doubled year over year across **Windows, Azure, Dynamics 365, and Office**, increasing the likelihoo...
Timeline
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28.05.2026 16:53 2 articles · 2h ago
Microsoft urges Coordinated Vulnerability Disclosure after Windows zero-day disclosures
Mitigation Patch UpdateMicrosoft urged researchers to use Coordinated Vulnerability Disclosure after multiple zero-day vulnerabilities affecting Windows components including Defender and BitLocker were publicly disclosed without prior vendor coordination. The company said the disclosures put customers at unnecessary risk and that its security teams are working around the clock to understand the impact, protect customers, and develop security updates; BlueHammer (CVE-2026-33825), RedSun (CVE-2026-41091), and UnDefend (CVE-2026-45498) are now under active exploitation in the wild.
Show sources
- Microsoft Slams Public Zero-Day Disclosures Amid GitHub Researcher Account Removal — thehackernews.com — 28.05.2026 16:53
- Microsoft Slams Public Zero-Day Disclosures Amid GitHub Researcher Account Removal — thehackernews.com — 28.05.2026 16:53