Patch tracker / KB5002858

KB5002858

Microsoft security update released 2026-05-12. Fixes 6 CVEs.

High

Download KB5002858

Get the official update for KB5002858. The download and file size for each supported product are on the Microsoft Update Catalog page.

Microsoft Update Catalog: download KB5002858 Microsoft support article

Update summary

Released

2026-05-12

CVEs fixed

6

Max CVSS

8.4

Severity

High

Exploitation and severity

Fixes 6 CVEs. Most severe CVSS 8.4 (High). EPSS exploit probability up to 4.4%.

Among the top half of tracked Microsoft updates by EPSS exploit probability.

What to do

Moderate priority: schedule it in your normal patch cycle. Senserva flags whether KB5002858 is missing on your devices.

CVEs fixed by this update

CVE-2026-35440 CVE-2026-40361 CVE-2026-40364 CVE-2026-40366 CVE-2026-40367 CVE-2026-40421

Affected products

Microsoft 365 Apps for Enterprise for 32-bit Systems
Microsoft Office 2019 for 32-bit editions
Microsoft Office 2019 for 64-bit editions

References

Microsoft support article Microsoft Security Update Guide

See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.

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Lexicon: the terms on this page

CVE: Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB: Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV: CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS: Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS: Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC: Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD: National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware: The vulnerability is linked to known ransomware activity.