Microsoft · Security update · October 13, 2026

KB5128896: October 2026 security update

KB5128896, released October 13, 2026, fixes 5 CVEs in Microsoft Exchange Server 2019 Cumulative Update 15. None of them is reported as exploited. Patch Radar priority: Urgent.

Urgent
CVEs closed
5
1 rated Critical
Exploited
0
None reported
Exploitation more likely
2
Vendor assessment
Highest EPSS
0.0139
72nd percentile

Priority of the 5 CVEs

Patch now 0 Urgent 2 High 3 Routine 0

Applies to

CVEs this fix closes

PriorityCVEComponentImpactCVSSEPSSExploitation
Urgent CVE-2026-70571 Microsoft Exchange Server Remote Code Execution 8.1 0.0139 More likely
Urgent CVE-2026-70279 Microsoft Exchange Server Spoofing 9.3 0.0129 More likely
High CVE-2026-77910 Microsoft Exchange Server Elevation of Privilege 8.8 0.0087 Exploitation Less Likely
High CVE-2026-87696 Microsoft Exchange Server Elevation of Privilege 7.5 0.0042 Exploitation Less Likely
High CVE-2026-87695 Microsoft Exchange Server Elevation of Privilege 7.8 0.0029 Exploitation Less Likely
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