Patch tracker / CVE reference / CVE-2026-42977
CVE-2026-42977
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 6 Microsoft security updates.
All about CVE-2026-42977: the Senserva AI read, whether it is exploited, the official patches, its change history, and the questions admins ask.
CVE-2026-42977 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 48%. Microsoft has shipped the fix: deploy one of the 6 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-2026-42977
One of a batch of four push notification service escalations on Windows 10 Version 1809 and Windows Server 2019, each rated Critical (CVSS 9.8). A cluster like this usually means a researcher swept one component and found systemic problems, which raises the odds that the techniques are well understood and reproducible. The 48 percent EPSS score reflects that. None are in the CISA KEV catalog yet.
Do this: Treat the four push notification CVEs as one patching task and confirm no 1809 device is excluded from the rollup.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-42977
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-42977
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 48%. CVSS 9.8 (Critical).
This CVE is among the top half of tracked Microsoft CVEs by EPSS exploit probability.
Official patch(es) for CVE-2026-42977
Elevated priority: high severity or a meaningful exploitation probability, sooner if an affected product is internet-facing. In Intune or Defender, confirm whether the fixing updates KB5093998, KB5094123, KB5094125, KB5094126, KB5094127, KB5094128 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-2026-42977. 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-2026-42977
Is CVE-2026-42977 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 48%.
What patch fixes CVE-2026-42977?
Microsoft fixed CVE-2026-42977 in KB5093998, KB5094123, KB5094125, KB5094126, KB5094127, KB5094128. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2026-42977?
Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019.
Can I ask my own AI about CVE-2026-42977?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-42977'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-2026-42977, 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.
