Microsoft · Security update · May 18, 2026

KB5087063: May 2026 security update

KB5087063, released May 18, 2026, fixes 2 CVEs across 2 products. None of them is reported as exploited. Patch Radar priority: High.

High

CVEs closed

None rated Critical

Exploited

None reported

Exploitation more likely

Microsoft's assessment

Highest EPSS

0.0077

55th percentile

Priority of the 2 CVEs

Patch now 0
                                Urgent 0
                                High 2
                                Routine 0

Applies to

Product
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2
Microsoft .NET Framework 4.8 on Windows Server 2012 R2

CVEs this fix closes

Priority	CVE	Component	Impact	CVSS	EPSS	Exploitation
High	CVE-2026-35433	.NET	Elevation of Privilege	7.3	0.0077	Exploitation Unlikely
High	CVE-2026-32177	.NET	Elevation of Privilege	7.3	0.0064	Exploitation Less Likely

Released the same day

KB5087048
Microsoft .NET Framework 3.5 on Windows Server 2012
KB5087049
Microsoft .NET Framework 3.5 on Windows Server 2012 R2
KB5087051
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for x64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025
KB5087053
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for x64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for ARM64-based Systems and 1 more
KB5087054
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for x64-based Systems
KB5087055
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 26H1 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H1 for x64-based Systems
KB5087058
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for x64-based Systems
KB5087059
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022
KB5087061
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems, Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019
KB5087062
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012
KB5087064
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for ARM64-based Systems, Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for x64-based Systems, Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for ARM64-based Systems and 1 more
KB5087065
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for x64-based Systems, Microsoft .NET Framework 4.8 on Windows Server 2016

Vendor advisory

https://support.microsoft.com/help/5087063

Our write-up

May 2026 Patch Tuesday: 137 Vulnerabilities, Zero Zero-Days, and a CVSS 9.9 in Dynamics 365

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