Microsoft · Security update · March 9, 2021

KB5000803: March 2021 cumulative update for Windows 10 1607

KB5000803, released March 9, 2021, fixes 36 CVEs across 10 products. One of them is being exploited (CVE-2021-26411); 1 on CISA KEV. Patch Radar priority: Patch now.

Patch now1 on CISA KEVKnown ransomware use2 publicly disclosed

CVEs closed

2 rated Critical

Exploited

CVE-2021-26411

Exploitation more likely

Microsoft's assessment

Highest EPSS

0.8167

99th percentile

Priority of the 36 CVEs

Patch now 1
                                Urgent 3
                                High 26
                                Routine 6

Applies to

Product	Build after install
Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems	14393.4283
Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems	14393.4283
Internet Explorer 11 on Windows Server 2016	14393.4283
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for 32-bit Systems	14393.4283
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for x64-based Systems	14393.4283
Microsoft Edge (EdgeHTML-based) on Windows Server 2016	14393.4283
Windows 10 Version 1607 for 32-bit Systems	14393.4283
Windows 10 Version 1607 for x64-based Systems	14393.4283
Windows Server 2016	14393.4283
Windows Server 2016 (Server Core installation)	14393.4283

CVEs this fix closes

Priority	CVE	Component	Impact	CVSS	EPSS	Exploitation
Patch now	CVE-2021-26411	Internet Explorer	Remote Code Execution	8.8	0.8167	KEVRansomwareDisclosedExploited
Urgent	CVE-2021-26877	Role: DNS Server	Remote Code Execution	9.8	0.1729	More likely
Urgent	CVE-2021-26897	Role: DNS Server	Remote Code Execution	9.8	0.1164	More likely
Urgent	CVE-2021-26868	Microsoft Graphics Component	Elevation of Privilege	7.8	0.0308	More likely
High	CVE-2021-26896	Role: DNS Server	Denial of Service	7.5	0.0785	Exploitation Less Likely
High	CVE-2021-26894	Role: DNS Server	Remote Code Execution	9.8	0.0776	Exploitation Less Likely
High	CVE-2021-26895	Role: DNS Server	Remote Code Execution	9.8	0.0776	Exploitation Less Likely
High	CVE-2021-26893	Role: DNS Server	Remote Code Execution	9.8	0.0702	Exploitation Less Likely
High	CVE-2021-27063	Role: DNS Server	Denial of Service	7.5	0.0673	Exploitation Less Likely
High	CVE-2021-26879	Role: Windows Hyper-V	Denial of Service	7.5	0.0387	Exploitation Less Likely
High	CVE-2021-26885	Windows WalletService	Elevation of Privilege	7.8	0.0349	Exploitation Less Likely
High	CVE-2021-26861	Microsoft Graphics Component	Remote Code Execution	7.8	0.0289	Exploitation Less Likely
High	CVE-2021-26881	Windows Media	Remote Code Execution	7.5	0.0283	Exploitation Less Likely
High	CVE-2021-26882	Windows Remote Access API	Elevation of Privilege	7.8	0.0211	Exploitation Less Likely
High	CVE-2021-27077	Microsoft Graphics Component	Elevation of Privilege	7.8	0.0144	DisclosedExploitation Less Likely
High	CVE-2021-26871	Windows WalletService	Elevation of Privilege	7.8	0.0143	Exploitation Less Likely
High	CVE-2021-26862	Windows Installer	Elevation of Privilege	7.0	0.0125	Exploitation Less Likely
High	CVE-2021-26866	Windows Update Stack	Elevation of Privilege	7.1	0.0116	Exploitation Less Likely
High	CVE-2021-26873	Windows User Profile Service	Elevation of Privilege	7.0	0.0115	Exploitation Less Likely
High	CVE-2021-26865	Windows Container Execution Agent	Elevation of Privilege	8.8	0.0108	Exploitation Less Likely
High	CVE-2021-26899	Windows UPnP Device Host	Elevation of Privilege	7.8	0.0097	Exploitation Less Likely
High	CVE-2021-1640	Windows Print Spooler Components	Elevation of Privilege	7.8	0.0095	Exploitation Less Likely
High	CVE-2021-26898	Windows Event Tracing	Elevation of Privilege	7.8	0.0087	Exploitation Less Likely
High	CVE-2021-26875	Microsoft Graphics Component	Elevation of Privilege	7.8	0.0087	Exploitation Less Likely
High	CVE-2021-26891	Windows Container Execution Agent	Elevation of Privilege	7.8	0.0087	Exploitation Less Likely

Released the same day

KB3101541
Microsoft Business Productivity Servers 2010 Service Pack 2
KB4484376
Microsoft Visio 2010 Service Pack 2 (32-bit editions), Microsoft Visio 2010 Service Pack 2 (64-bit editions)
KB4486673
Microsoft Visio 2013 Service Pack 1 (32-bit editions), Microsoft Visio 2013 Service Pack 1 (64-bit editions)
KB4493151
Microsoft Visio 2016 (32-bit edition), Microsoft Visio 2016 (64-bit edition)
KB4493177
Microsoft SharePoint Foundation 2013 Service Pack 1
KB4493199
Microsoft SharePoint Enterprise Server 2016
KB4493224
Microsoft PowerPoint 2016 (32-bit edition), Microsoft PowerPoint 2016 (64-bit edition)
KB4493227
Microsoft PowerPoint 2013 RT Service Pack 1, Microsoft PowerPoint 2013 Service Pack 1 (32-bit editions), Microsoft PowerPoint 2013 Service Pack 1 (64-bit editions)
KB4493230
Microsoft SharePoint Server 2019
KB4493231
Microsoft SharePoint Server 2019
KB4493232
Microsoft SharePoint Enterprise Server 2016
KB4493238
Microsoft SharePoint Foundation 2013 Service Pack 1

Vendor advisory

https://support.microsoft.com/help/5000803

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