Patch tracker / KB5074993
KB5074993: Microsoft Exchange Server Subscription Security Update (February 2026)
KB5074993 is a Medium security update for Microsoft Exchange Server Subscription, released 2026-02-10. It closes 1 CVE with a maximum CVSS of 6.5. Get it from the Microsoft Update Catalog below, and see where it sits against the rest of the month on the patch tracker.
Update summary
New to these terms? How the Microsoft patching tools fit together, this month's Patch Tuesday summary, and every update ranked by real-world risk.
Senserva AI Opinion for KB5074993
KB5074993 patches a single vulnerability (CVE-2026-21527) across three on-premises Exchange builds: Subscription Edition RTM, 2016 CU23, and 2019 CU15. The rating is Medium with a CVSS of 6.5 and an EPSS of 8 percent, and it is not in CISA KEV nor linked to ransomware, so this is a routine servicing update rather than an emergency. It matters mainly because Exchange servers are internet-facing mail infrastructure where even Medium-severity flaws accumulate risk if left unpatched.
Do this: Schedule this update on your on-premises Exchange 2016 CU23, 2019 CU15, and Subscription Edition RTM servers during your next maintenance window, confirming each host is on the exact supported cumulative update level first.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5074993
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5074993
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.
Exploitation and severity
Fixes 1 CVE. Most severe CVSS 6.5 (Medium). EPSS exploit probability up to 7.7%.
Among the top half of tracked Microsoft updates by EPSS exploit probability.
What to do
Lower priority: patch in your normal cycle. Senserva flags whether KB5074993 is missing on your devices.
Check if KB5074993 is installed
Copy-paste PowerShell: one machine, or your whole estate in one pass. No output means the update is not installed.
Get-HotFix covers Windows updates. Office, SharePoint, and Exchange server updates show under installed updates in Programs and Features, or check the Update Catalog history.
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-2026-21527 | Medium | 6.5 | 7.7% | No |
Affected products
Also released in February 2026
The highest-risk updates from the same release:
The full month, summarized: Microsoft Patch Tuesday.
Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.