Patch tracker / CVE reference / CVE-2026-20946

CVE-2026-20946

CVE-2026-20946 is a high severity Microsoft vulnerability with a CVSS score of 7.8. Microsoft has shipped the fix: deploy the update below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

High

High severity Microsoft vulnerability, CVSS 7.8. Fixed by 1 Microsoft security update.

Senserva AI read on CVE-2026-20946 Official patches for CVE-2026-20946 Change history Admin questions

Risk summary

CVSS base

7.8

EPSS exploit probability

<1%

Severity

High

Senserva AI Opinion for CVE-2026-20946

This Excel remote code execution flaw differs from the Office Online Server cluster by targeting the desktop side: Office 2019 and Microsoft 365 Apps for Enterprise. It is High Severity at CVSS 7.8, with EPSS at just 1 percent and no known exploitation. Malicious spreadsheets remain a top phishing payload, so routine patching still closes a well-trodden door.

Do this: Let Microsoft 365 Apps update through its servicing channel and verify Office 2019 machines are not stuck on old builds.

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

Senserva AI Opinion and rich prompt for CVE-2026-20946

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-2026-20946 (source: https://senserva.com/cve/CVE-2026-20946.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-20946: High severity Microsoft vulnerability, CVSS 7.8
- EPSS 30-day exploitation probability: <1%
- Actively exploited (CISA KEV): no
- Fixed by: KB5002831
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: not in the CISA KEV catalog, EPSS under 1%.

Fixed by KB5002831. 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.

Updated August 7, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2026-20946

Published

2026-01-13

Last revised

2026-01-13

Changes tracked

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 <1%. CVSS 7.8 (High).

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

Official patch(es) for CVE-2026-20946

Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing update KB5002831 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security update below to fix CVE-2026-20946. 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.

KB5002831

Affected products

Fixed by the same update

If you are patching CVE-2026-20946, the same update also fixes these:

CVE-2026-20950 CVE-2026-20957

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.