Patch tracker / KB5002776

KB5002776: Office Online Server Security Update (September 2025)

KB5002776 is a High security update for Office Online Server, released 2025-09-09. It closes 6 CVEs with a maximum CVSS of 7.8. It is the tenth largest of the 32 updates Microsoft shipped that month, by CVEs closed.

Update summary

High
2025-09-09
Released
6
CVEs fixed
7.8
Max CVSS v3
High
Severity
Deploy this cycle
Fixes 6 CVEs for Office Online Server. No confirmed in-the-wild exploitation in this set today.

Fixes 6 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.

Senserva AI Opinion for KB5002776

KB5002776 is a September 2025 bundle patching six CVEs across Office Online Server and Office 2019 in both 32-bit and 64-bit editions, with the worst rated High severity at CVSS 7.8. Anyone running these Office builds is exposed, though EPSS is only 1 percent and none of the six CVEs appear in CISA KEV or are linked to ransomware. The spread across Office Online Server plus standalone Office 2019 means both server and desktop deployments need the update.

Do this: Deploy KB5002776 to Office Online Server hosts and all Office 2019 32-bit and 64-bit clients through your normal patch cycle this window.

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

Senserva AI Opinion and rich prompt for KB5002776

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

Full tracking and change history for KB5002776

Released
2025-09-09
Last changed
2025-09-09
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 KB5002776 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-2025-54896High7.8<1%No
CVE-2025-54898High7.8<1%No
CVE-2025-54900High7.8<1%No
CVE-2025-54902High7.8<1%No
CVE-2025-54903High7.8<1%No
CVE-2025-54904High7.8<1%No

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.