Microsoft · Security update · May 12, 2026

KB5002858: May 2026 security update

KB5002858, released May 12, 2026, fixes 6 CVEs across 2 products. None of them is reported as exploited. Patch Radar priority: Urgent.

Urgent
CVEs closed
6
4 rated Critical
Exploited
0
None reported
Exploitation more likely
2
Vendor assessment
Highest EPSS
0.0442
91st percentile

Priority of the 6 CVEs

Patch now 0 Urgent 4 High 0 Routine 2

Applies to

CVEs this fix closes

PriorityCVEComponentImpactCVSSEPSSExploitation
Urgent CVE-2026-40364 Microsoft Office Word Remote Code Execution 8.4 0.0442 More likely
Urgent CVE-2026-40361 Microsoft Office Remote Code Execution 8.4 0.0061 More likely
Urgent CVE-2026-40367 Microsoft Office Word Remote Code Execution 8.4 0.0045 Exploitation Unlikely
Urgent CVE-2026-40366 Microsoft Office Word Remote Code Execution 8.4 0.0038 Exploitation Less Likely
Routine CVE-2026-40421 Microsoft Office Word Information Disclosure 4.3 0.0062 Exploitation Less Likely
Routine CVE-2026-35440 Microsoft Office Word Information Disclosure 5.5 0.0045 Exploitation Less Likely
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