Patch tracker / CVE reference / CVE-2026-20938
CVE-2026-20938
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 2 Microsoft security updates.
All about CVE-2026-20938: the Senserva AI read, whether it is exploited, the official patches, its change history, and the questions admins ask.
CVE-2026-20938 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 73%. Microsoft has shipped the fix: deploy one of the 2 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
Risk summary
Senserva provides Three Free Unlimited Audits, including all tenants and full Claude MCP.Start my Audit
Senserva AI Opinion for CVE-2026-20938
This flaw undermines a security boundary rather than just a service: it allows elevation of privilege against Windows Virtualization-Based Security enclaves on Windows 11 24H2 and 25H2. It is rated Critical Severity at CVSS 9.8 with a 73 percent EPSS score. VBS enclaves exist to protect secrets like credentials from a compromised OS, so a break here erodes the protection layer itself.
Do this: Patch Windows 11 24H2 and 25H2 devices that rely on VBS features such as Credential Guard first.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-20938
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-20938
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 73%. CVSS 9.8 (Critical).
This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability.
Official patch(es) for CVE-2026-20938
High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5073455, KB5074109 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-2026-20938. 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-2026-20938
Is CVE-2026-20938 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 73%.
What patch fixes CVE-2026-20938?
Microsoft fixed CVE-2026-20938 in KB5073455, KB5074109. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2026-20938?
Windows 10 Version 1809 for 32-bit Systems, Windows 11 Version 25H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems.
Can I ask my own AI about CVE-2026-20938?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-20938'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-2026-20938, 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.
