Patch tracker / CVE reference / CVE-2026-42897
CVE-2026-42897
Updated July 21, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
In the top 10 of the Senserva CVE Ranking (as of 2026-07-21)High severity Microsoft vulnerability, CVSS 8.8. Fixed by 4 Microsoft security updates.
All about CVE-2026-42897: the Senserva AI read, whether it is exploited, the official patches, its change history, and the questions admins ask.
CVE-2026-42897 is a high severity Microsoft vulnerability with a CVSS score of 8.8. It is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it in the wild, which makes it a fix-first item. Microsoft has shipped the fix: deploy one of the 4 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
Risk summary
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Senserva AI Opinion for CVE-2026-42897
This is a spoofing flaw in on-premises Exchange Server (2016 CU23, 2019 CU14 and CU15) that CISA added to its Known Exploited Vulnerabilities catalog on 2026-05-15, so real-world exploitation is confirmed despite the modest 6 percent EPSS score. Any organization still running these on-prem Exchange builds is exposed, and spoofing on a mail server can be leveraged to impersonate users or relay through trusted identities. The KEV listing plus a Severity of High (CVSS 8.8) makes this a patch-now item rather than a wait-and-test one.
Do this: Identify all Exchange Server 2016 CU23 and 2019 CU14/CU15 hosts and apply Microsoft's security update for CVE-2026-42897 immediately, prioritizing internet-facing servers.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-42897
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-42897
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
Exploitation and severity
Listed in the CISA Known Exploited Vulnerabilities catalog, confirmed exploited in the wild. EPSS exploit probability 5.6%. CVSS 8.8 (High).
This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability, and one of 1 actively-exploited CVEs in June 2026.
Official patch(es) for CVE-2026-42897
Treat as urgent: it is being exploited in the wild (CISA KEV), so patch ahead of items that are not. In Intune or Defender, confirm whether the fixing updates KB5094139, KB5094140, KB5094142, KB5094144 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.
Apply the Microsoft security updates below to fix CVE-2026-42897. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.
Affected products
Common questions about CVE-2026-42897
Is CVE-2026-42897 actively exploited?
Yes. CVE-2026-42897 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed. Its EPSS exploit probability is 5.6%.
What patch fixes CVE-2026-42897?
Microsoft fixed CVE-2026-42897 in KB5094139, KB5094140, KB5094142, KB5094144. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2026-42897?
Microsoft Exchange Server 2019 Cumulative Update 14, Microsoft Exchange Server 2019 Cumulative Update 15, Microsoft Exchange Server Subscription Edition RTM.
Can I ask my own AI about CVE-2026-42897?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-42897's key facts: severity, CVSS, EPSS exploit probability, CISA KEV status, and the fixing KB. Copy it into Claude, ChatGPT, or Copilot for a triage plan; the data is refreshed three times a day (5 AM, 12:30 PM, and 7 PM US Central).
Fixed by the same updates
If you are patching CVE-2026-42897, the same updates also fix these:
Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.
