Patch tracker / CVE reference / CVE-2026-42896
CVE-2026-42896
Updated July 21, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Critical severity Microsoft vulnerability, CVSS 9.8. Fixed by 4 Microsoft security updates.
All about CVE-2026-42896: the Senserva AI read, whether it is exploited, the official patches, its change history, and the questions admins ask.
CVE-2026-42896 is a critical severity Microsoft vulnerability with a CVSS score of 9.8. Its EPSS score puts the probability of exploitation in the next 30 days at 72%. 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-2026-42896
This Desktop Window Manager escalation reaches the newest server platform: Windows Server 2025 Server Core alongside Windows 11 Version 25H2, rated Critical (CVSS 9.8) with EPSS at 72 percent. DWM on servers gets less attention because sessions are rare there, but the component is present and the higher EPSS score on this variant outranks its 26H1 cousins. Fresh Server 2025 deployments are the population most likely to be missed.
Do this: Add Server 2025 hosts to the DWM patching sweep explicitly, since server-side compositor bugs are easy to dismiss as client-only issues.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-42896
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-42896
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
Not in the CISA KEV catalog. EPSS exploit probability 72%. CVSS 9.8 (Critical).
This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability.
Official patch(es) for CVE-2026-42896
High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5087423, KB5087539, KB5089466, KB5089549 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-2026-42896. 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-2026-42896
Is CVE-2026-42896 actively exploited?
It is not currently listed in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score puts the probability of exploitation in the next 30 days at 72%.
What patch fixes CVE-2026-42896?
Microsoft fixed CVE-2026-42896 in KB5087423, KB5087539, KB5089466, KB5089549. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2026-42896?
Windows 11 Version 25H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows Server 2025 (Server Core installation).
Can I ask my own AI about CVE-2026-42896?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-42896'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-2026-42896, 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.
