Patch tracker / CVE reference / CVE-2026-50331

CVE-2026-50331

CVE-2026-50331 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 7.8 (High). Microsoft has shipped the fix: deploy one of the 7 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High

7.8

CVSS v3

4.9%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 4.9%. CVSS 7.8 (High).

This CVE is among the top half of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2026-50331

CVE-2026-50331 is an elevation of privilege flaw in the Windows Application Model Core API, carrying a Critical rating with an unusually high CVSS of 9.9 for a privilege escalation bug. Exposure is limited to Windows 10 Version 1809 (32-bit and x64) and Windows Server 2019, so older 1809-based deployments are the specific concern here. It is not in CISA KEV and shows no ransomware use, with EPSS at 7 percent, meaning there is time to patch deliberately rather than react to active exploitation.

Do this: Inventory all Windows 10 1809 and Server 2019 hosts and apply the Microsoft security update for CVE-2026-50331 to them first.

AI-generated from public data, 2026-07-24. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-50331

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I am an IT admin assessing a vulnerability. Facts for CVE-2026-50331 (source: https://senserva.com/cve/CVE-2026-50331.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed daily (early morning US Central)):
- CVE-2026-50331: Microsoft vulnerability, Microsoft rating Important, CVSS 7.8 (High)
- EPSS 30-day exploitation probability: 4.9%
- Actively exploited (CISA KEV): no
- Fixed by: KB5099535, KB5099536, KB5099538, KB5099539, KB5099540, KB5101649, KB5101650
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) What to patch or mitigate first. 4) How to check whether my devices are exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Schedule normally

No exploitation observed as of 2026-10-14: not in the CISA KEV catalog, EPSS 5%.

Fixed by KB5099535 and 6 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.

Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Official patch(es) for CVE-2026-50331

Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing updates KB5099535, KB5099536, KB5099538, KB5099539, KB5099540, KB5101649, KB5101650 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-2026-50331. 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.

KB5099535 KB5099536 KB5099538 KB5099539 KB5099540 KB5101649 KB5101650

Scope and sources

Affected products

Fixed by the same updates

CVE-2026-56155 CVE-2026-32202 CVE-2026-57092 CVE-2026-42990 CVE-2026-49172 CVE-2026-50447 CVE-2026-50518 CVE-2026-54990

Authoritative references

Official CVE record (cve.org)NVD detail Microsoft MSRC FIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.