KB5121575: what it fixes and who gets it

KB5121575 is a security update from Microsoft's August 2026 release for Microsoft Exchange Server 2019 Cumulative Update 14.

Microsoft data read
7CVEs fixed
1rated Critical
0already exploited
Yesrestart required

Should you install it?

Yes. It closes holes Microsoft rates Critical, the most serious rating it uses. Windows Update installs it automatically on supported home PCs.

If the installation fails or the PC misbehaves afterwards, note the exact error code first: the fix depends on it. Our update troubleshooting guides are linked on this page.

Security fixes in KB5121575

CVETypeCVSSSeverity
CVE-2026-62911Microsoft Exchange Server Elevation of Privilege VulnerabilityElevation of Privilege8.0Critical
CVE-2026-62913Microsoft Exchange Server Remote Code Execution VulnerabilityRemote Code Execution8.8Important
CVE-2026-62914Microsoft Exchange Server Spoofing VulnerabilitySpoofing7.3Important
CVE-2026-62910Microsoft Exchange Server Elevation of Privilege VulnerabilityElevation of Privilege7.2Important
CVE-2026-62912Microsoft Exchange Server Denial of Service VulnerabilityDenial of Service6.5Important
CVE-2026-62915Microsoft Exchange Server Security Feature Bypass VulnerabilitySecurity Feature Bypass6.5Important
CVE-2026-65813Microsoft Exchange Server Elevation of Privilege VulnerabilityElevation of Privilege6.5Important

Questions and experiences

Ask about this page: members and our editors answer. Reading is open; writing needs a free account.

0 comments

…

4,322 members already hereThey read, write, comment and vote. 0 verified · 31 joined this year

Cookies

We use essential cookies to run the platform. Analytics and marketing cookies are only turned on once you consent — you can change your choice at any time.