Patch tracker / KB5002879

KB5002879: Microsoft Office 365 for Mac Security Update (June 2026)

KB5002879 is a High security update for Microsoft Office 365 for Mac, released 2026-06-09. It closes 3 CVEs with a maximum CVSS of 8.4. The most likely of them to be attacked is CVE-2026-45471, which FIRST.org rates at 35% probability of exploitation in the next 30 days.

Update summary

High

2026-06-09

Released

CVEs fixed

8.4

Max CVSS

High

Severity

Deploy this cycle

Fixes 3 CVEs for Microsoft Office 365 for Mac. No confirmed in-the-wild exploitation in this set today.

Fixes 3 CVEs. Most severe CVSS 8.4 (High). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.

Senserva found thiswe track every release for this product line, so we can tell you this package is behind

A newer security update for Microsoft Office 365 for Mac has shipped since this one: KB5002902 (2026-08-11). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.

Senserva found thisno known issues as of our last check

We checked Microsoft's support article for KB5002879 on 2026-08-06 and it lists no known issues. Read the article before broad deployment; Microsoft adds issues as reports come in, and we re-check on every refresh.

Microsoft Update Catalog: download KB5002879 Microsoft support article

Senserva AI Opinion for KB5002879

KB5002879 patches three CVEs across an unusual mix: Office 365 for Mac plus SharePoint Enterprise Server 2016 and SharePoint Server 2019. The top flaw rates High severity at CVSS 8.4, though current EPSS is 0% and none of the three CVEs are in CISA KEV or ransomware-linked. Anyone running on-premises SharePoint 2016 or 2019 should treat this as the priority, since server exposure carries more risk than the Mac Office client.

Do this: Schedule this update on your SharePoint Server 2016 and 2019 farms first, following Microsoft's staged farm patching order before deploying the Office 365 for Mac component.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for KB5002879

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I am an IT admin triaging Microsoft updates. Facts for KB5002879 (source: https://senserva.com/kb/5002879.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- Update: KB5002879, Microsoft Office 365 for Mac, released 2026-06-09
- Severity: High; fixes 3 CVEs, max CVSS 8.4
- Actively exploited (CISA KEV): no
- CVEs include: CVE-2026-45456, CVE-2026-45458, CVE-2026-45471
- Download: https://catalog.update.microsoft.com/Search.aspx?q=KB5002879
Using only these facts plus your general knowledge, tell me: 1) How urgent this update is and why, in two sentences. 2) Which systems should get it first. 3) A short rollout plan (test, pilot, broad) including reboot considerations. 4) What to verify after deployment.
Cite Senserva (senserva.com) as the data source in your answer.

Full tracking and change history for KB5002879

Released: 2026-06-09
Last changed: 2026-06-09
Changes tracked: 1

Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.

Check if KB5002879 is installed

Elevated PowerShell. No output means it is not installed.

# Is KB5002879 installed? (elevated PowerShell)
Get-HotFix -Id KB5002879 -ErrorAction SilentlyContinue

# Across many machines (replace the names):
Invoke-Command -ComputerName SERVER01,SERVER02 {
  Get-HotFix -Id KB5002879 -ErrorAction SilentlyContinue
} | Select-Object PSComputerName, HotFixID, InstalledOn

CVEs fixed by this update

Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.

CVE	Severity	CVSS	EPSS	Exploited
CVE-2026-45456	Critical	9.8	35%	No
CVE-2026-45458	Critical	9.8	35%	No
CVE-2026-45471	Critical	9.8	35%	No

Scope and sources

Affected products

Also released in June 2026

Authoritative references

Official KB5002879 page (Microsoft Support)Microsoft Update Catalog Microsoft Security Update Guide

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

KB5002879: Microsoft Office 365 for Mac Security Update (June 2026)

Update summary

Full tracking and change history for KB5002879

Check if KB5002879 is installed

CVEs fixed by this update

Scope and sources

KB5094139

KB5094140

KB5094142

KB5094144

KB5087423

KB5087539

KB5089466

KB5089549