Patch tracker / KB5002824

KB5002824: Office Online Server Security Update (January 2026)

KB5002824 is a High security update for Office Online Server, released 2026-01-13. It closes 3 CVEs with a maximum CVSS of 7.8. It is the 18th largest of the 40 updates Microsoft shipped that month, by CVEs closed.

Update summary

High
2026-01-13
Released
3
CVEs fixed
7.8
Max CVSS v3
High
Severity
Deploy this cycle
Fixes 3 CVEs for Office Online Server. No confirmed in-the-wild exploitation in this set today.

Fixes 3 CVEs. 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 KB5002824Microsoft support article
Senserva AI Opinion for KB5002824

KB5002824 patches three CVEs across Office Online Server and Office 2019 in both 32-bit and 64-bit editions, with the most serious rated High at CVSS 7.8. Exposure spans both the server-side Office Online Server component and desktop Office 2019 installs, so a single KB touches two distinct deployment types. None of the three CVEs are in CISA KEV or linked to ransomware, and the highest EPSS sits at 1 percent, indicating no observed exploitation yet.

Do this: Deploy KB5002824 to your Office Online Server instances first, since a shared server component reaches more users than individual Office 2019 desktops.

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

Senserva AI Opinion and rich prompt for KB5002824

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

Full tracking and change history for KB5002824

Released
2026-01-13
Last changed
2026-01-13
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 KB5002824 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-2026-20950High7.8<1%No
CVE-2026-20955High7.8<1%No
CVE-2026-20957High7.8<1%No

Scope and sources

Affected products
Also released in January 2026

KB5002822

6 CVEs · Critical · exploited

KB5002825

7 CVEs · Critical · exploited

KB5002828

7 CVEs · Critical · exploited

KB5073379

86 CVEs · Critical · exploited

KB5073450

80 CVEs · Critical · exploited

KB5073455

80 CVEs · Critical · exploited

KB5073457

78 CVEs · Critical · exploited

KB5073722

54 CVEs · Critical · exploited

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5002824 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.