Patch tracker / KB5094140
KB5094140: Microsoft Exchange Server 2016 Cumulat Security Update (June 2026)
KB5094140 is a High security update for Microsoft Exchange Server 2016 Cumulat, released 2026-06-09. It closes 8 CVEs with a maximum CVSS of 8.8. At least one of them is actively exploited (CISA KEV), so this is a deploy-first update. The most likely of them to be attacked is CVE-2026-42897, which FIRST.org rates at 70% probability of exploitation in the next 30 days.
Update summary
Fixes 8 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 8.8 (High). EPSS exploit probability up to 70%. Among the top 25% of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Microsoft Exchange Server 2016 Cumulative Update 23 has shipped since this one: KB5103212 (2026-07-14). 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 KB5094140 on 2026-08-05 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.
KB5094140 patches 8 CVEs across Exchange Server 2019 CU14 and CU15 plus the Subscription Edition RTM, with a highest Severity of High at CVSS 8.8. One of these CVEs is listed in the CISA Known Exploited Vulnerabilities catalog, meaning attackers are already using it in the wild, though none are tied to ransomware campaigns. Any organization running on-premises Exchange is exposed, and Exchange remains a repeatedly targeted internet-facing service.
Do this: Schedule this update on your Exchange 2019 CU14, CU15, and Subscription Edition RTM servers now, prioritizing internet-facing mailbox and transport roles because a fixed CVE is already in the CISA KEV catalog.
AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5094140
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5094140
- Released
- 2026-06-09
- Last changed
- 2026-08-03
- Changes tracked
- 3
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 KB5094140 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.
| CVE | Severity | CVSS | EPSS | Exploited |
|---|---|---|---|---|
| CVE-2026-42897 | High | 8.8 | 70% | KEV |
| CVE-2026-45500 | Critical | 9.6 | 70% | No |
| CVE-2026-45501 | Critical | 9.6 | 70% | No |
| CVE-2026-45502 | Critical | 9.6 | 70% | No |
| CVE-2026-45503 | Critical | 9.6 | 70% | No |
| CVE-2026-45504 | Critical | 9.6 | 70% | No |
| CVE-2026-45583 | Critical | 9.6 | 70% | No |
| CVE-2026-47631 | Critical | 9.6 | 70% | No |
Scope and sources
- Affected products
- Also released in June 2026
KB5094139
8 CVEs · High · exploitedKB5094142
8 CVEs · High · exploitedKB5094144
8 CVEs · High · exploitedKB5087423
66 CVEs · CriticalKB5087539
66 CVEs · CriticalKB5089466
61 CVEs · CriticalKB5089549
61 CVEs · CriticalKB5093998
158 CVEs · CriticalThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.