Patch tracker / KB5002718

KB5002718: Office Online Server Security Update (March 2026)

KB5002718 is a High security update for Office Online Server, released 2026-03-10. It closes 1 CVE with a maximum CVSS of 7.8. It is the 32nd largest of the 43 updates Microsoft shipped that month, by CVEs closed.

Update summary

High
2026-03-10
Released
1
CVEs fixed
7.8
Max CVSS v3
High
Severity
Deploy this cycle
Fixes 1 CVE for Office Online Server. No confirmed in-the-wild exploitation in this set today.

Fixes 1 CVE. Most severe CVSS 7.8 (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 Office Online Server has shipped since this one: KB5002884 (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.

Microsoft Update Catalog: download KB5002718Microsoft support article
Senserva AI Opinion for KB5002718

KB5002718 patches a single flaw, CVE-2026-26108, rated High severity at CVSS 7.8, across Office Online Server and both 32-bit and 64-bit Office 2019. The exposure spans server-side Office rendering and desktop installs, so a shared Office Online Server deployment widens the blast radius beyond individual workstations. Exploitation is unproven right now with EPSS at 0 percent and no CISA KEV or ransomware association, making this a schedule-and-patch item rather than an emergency.

Do this: Deploy KB5002718 to your Office Online Server instances first, then roll it to Office 2019 desktop clients through your normal patch cycle.

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

Senserva AI Opinion and rich prompt for KB5002718

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

Full tracking and change history for KB5002718

Released
2026-03-10
Last changed
2026-03-10
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 KB5002718 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.

CVESeverityCVSSEPSSExploited
CVE-2026-26108High7.8<1%No

Scope and sources

Affected products
Also released in March 2026

KB5002843

3 CVEs · High

KB5002845

4 CVEs · High

KB5002850

4 CVEs · High

KB5077464

2 CVEs · High

KB5077465

2 CVEs · High

KB5077466

3 CVEs · High

KB5077468

3 CVEs · High

KB5077469

2 CVEs · High

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5002718 page (Microsoft Support)Microsoft Update CatalogMicrosoft Security Update Guide

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

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
Provided as is, without warranty; verify against the vendor advisory before acting. Data notice and terms.