Patch tracker / KB5128895

KB5128895: Exchange Server Subscription Edition Security Update (October 2026)

KB5128895 is a Critical security update for Exchange Server Subscription Edition, released 2026-10-13. It closes 6 CVEs with a maximum CVSS of 9.3. It is the 42nd largest of the 55 updates Microsoft shipped that month, by CVEs closed.

Update summary

Critical

2026-10-13

Released

CVEs fixed

9.3

Max CVSS v3

Critical

Severity

Deploy this cycle

Fixes 6 CVEs for Exchange Server Subscription Edition. No confirmed in-the-wild exploitation in this set today.

Fixes 6 CVEs. Most severe CVSS 9.3 (Critical).

Microsoft Update Catalog: download KB5128895 Microsoft support article

Senserva AI Opinion and rich prompt for KB5128895

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 KB5128895 (source: https://senserva.com/kb/5128895.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed daily (early morning US Central)):
- Update: KB5128895, Exchange Server Subscription Edition, released 2026-10-13
- Severity: Critical; fixes 6 CVEs, max CVSS 9.3
- Actively exploited (CISA KEV): no
- CVEs include: CVE-2026-70279, CVE-2026-70571, CVE-2026-77910, CVE-2026-87692, CVE-2026-87695, CVE-2026-87696
- Download: https://catalog.update.microsoft.com/Search.aspx?q=KB5128895
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 KB5128895

Released: 2026-10-13
Last changed: 2026-10-13
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 KB5128895 is installed

Elevated PowerShell. No output means it is not installed.

# Is KB5128895 installed? (elevated PowerShell)
Get-HotFix -Id KB5128895 -ErrorAction SilentlyContinue

# Across many machines (replace the names):
Invoke-Command -ComputerName SERVER01,SERVER02 {
  Get-HotFix -Id KB5128895 -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-2026-70279	Critical	9.3	-	No
CVE-2026-77910	High	8.8	-	No
CVE-2026-70571	High	8.1	-	No
CVE-2026-87692	High	7.8	-	No
CVE-2026-87695	High	7.8	-	No
CVE-2026-87696	High	7.5	-	No

What the press says about this update

Trusted-source coverage of the CVEs this update fixes, pulled live from their own feeds.

“Microsoft’s October 2026 Patch Tuesday addresses 1407 CVEs (CVE-2026-96951)” Tenable, 2026-10-13

“The October 2026 Security Update Review” Zero Day Initiative, 2026-10-13

Scope and sources

Affected products

Microsoft Exchange Server Subscription Edition RTM

Also released in October 2026

Authoritative references

Official KB5128895 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.

KB5128895: Exchange Server Subscription Edition Security Update (October 2026)

Update summary

Full tracking and change history for KB5128895

Check if KB5128895 is installed

CVEs fixed by this update

What the press says about this update

Scope and sources

KB5126646

KB5126651

KB5126653

KB5126655

KB5126657

KB5126836

KB5126868

KB5127646