Patch tracker / KB5094142
KB5094142: Microsoft Exchange Server 2016 Cumulat Security Update (June 2026)
KB5094142 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 KB5094142 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.
KB5094142 patches 8 CVEs across on-premises Exchange Server 2019 (Cumulative Updates 14 and 15) and the new Subscription Edition RTM, with a highest severity of High at CVSS 8.8. One of these CVEs is already listed in CISA KEV, meaning it is being exploited in the wild, though none are currently tied to ransomware. Internet-facing Exchange servers are directly exposed, and the confirmed exploitation raises the urgency well above a routine cumulative update.
Do this: Apply KB5094142 to all Exchange Server 2019 CU14/CU15 and Subscription Edition hosts now, prioritizing any internet-facing servers given the KEV-listed CVE.
AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5094142
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5094142
- 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 KB5094142 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 · exploitedKB5094140
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.