Patch tracker / KB5002884
KB5002884: Office Online Server Security Update (July 2026)
KB5002884 is a High security update for Office Online Server, released 2026-07-14. It closes 57 CVEs with a maximum CVSS of 8.8. It is the tenth largest of the 61 updates Microsoft shipped that month, by CVEs closed.
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Update summary
Fixes 57 CVEs. Most severe CVSS 8.8 (High). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Office Online Server has shipped since this one: KB5002928 (2026-10-13). 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 KB5002884 on 2026-10-11 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.
KB5002884 is a security update for Office Online Server in the July 2026 Patch Tuesday cycle, affecting organizations that host their own web-based viewing and editing of Office documents. The per-update CVE detail is still provisional, so the specific flaws and their severity are not yet published, and no named zero-day maps to this update. Office Online Server sits in a document-rendering path that often processes untrusted files, which makes it a meaningful target even without confirmed CVE specifics.
Do this: Identify your Office Online Server farm hosts and stage KB5002884 in a test farm now so you can deploy once Microsoft publishes the CVE detail for this cycle.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5002884
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5002884
- Released
- 2026-07-14
- Last changed
- 2026-10-16
- Changes tracked
- 4
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 KB5002884 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.
Scope and sources
- Affected products
- Also released in July 2026
KB5099444
186 CVEs · Critical · exploitedKB5099445
175 CVEs · Critical · exploitedKB5099535
262 CVEs · Critical · exploitedKB5099536
388 CVEs · Critical · exploitedKB5099538
312 CVEs · Critical · exploitedKB5099539
314 CVEs · Critical · exploitedKB5099540
326 CVEs · Critical · exploitedKB5101649
382 CVEs · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.