Patch tracker / KB5002878
KB5002878: Microsoft Office 365 for Mac Security Update (June 2026)
KB5002878 is a High security update for Microsoft Office 365 for Mac, released 2026-06-09. It closes 9 CVEs with a maximum CVSS of 8.4. The most likely of them to be attacked is CVE-2026-45475, which FIRST.org rates at 35% probability of exploitation in the next 30 days.
Update summary
Fixes 9 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.
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.
We checked Microsoft's support article for KB5002878 on 2026-08-05 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.
KB5002878 bundles nine CVEs across an unusual mix of Office 365 for Mac and on-premises SharePoint Enterprise Server 2016 and 2019, so it lands on two very different administration tracks at once. The top issue rates High at CVSS 8.4, but EPSS is 0% and none of the nine are in the CISA KEV catalog or tied to ransomware. That means this is a solid scheduled fix rather than a drop-everything emergency.
Do this: Patch your SharePoint 2016 and 2019 farms and push the Office 365 for Mac update through your normal June cycle, coordinating the two separate deployment channels this KB touches.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5002878
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5002878
- 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 KB5002878 is installed
Elevated PowerShell. No output means it is not installed.
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-2026-44819 | Critical | 9.8 | 35% | No |
| CVE-2026-44821 | Critical | 9.8 | 35% | No |
| CVE-2026-44824 | Critical | 9.8 | 35% | No |
| CVE-2026-45475 | Critical | 9.8 | 35% | No |
| CVE-2026-45485 | Critical | 9.8 | 35% | No |
| CVE-2026-45461 | High | 8.4 | <1% | No |
| CVE-2026-45463 | High | 8.4 | <1% | No |
| CVE-2026-45472 | High | 8.4 | <1% | No |
| CVE-2026-45474 | High | 8.4 | <1% | No |
Scope and sources
- Affected products
- Also released in June 2026
KB5094139
8 CVEs · High · exploitedKB5094140
8 CVEs · High · exploitedKB5094142
8 CVEs · High · exploitedKB5094144
8 CVEs · High · exploitedKB5087423
66 CVEs · CriticalKB5087539
66 CVEs · CriticalKB5089466
61 CVEs · CriticalKB5089549
61 CVEs · CriticalThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.