Patch tracker / CVE reference / CVE-2026-20841

CVE-2026-20841

A Remote Code Execution vulnerability affecting Windows Notepad.

High

High severity Microsoft vulnerability, CVSS 7.8.

Senserva AI read on CVE-2026-20841How to fix CVE-2026-20841Change historyAdmin questions

Risk summary

CVSS base
7.8
Severity
High
Actively exploited
Not listed
Schedule normally
No exploitation observed: not in the CISA KEV catalog, EPSS under 1%.
No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.
Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Updated July 26, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Senserva AI Opinion for CVE-2026-20841

CVE-2026-20841 is a remote code execution flaw in Windows Notepad rated Severity High with a CVSS score of 7.8, meaning a crafted file opened in Notepad could run attacker code in the user context. Because Notepad ships with every Windows install and is a default handler for text files, any user who opens an untrusted document is exposed. It is not listed in CISA KEV and has no known ransomware use, so this is a patch-before-exploitation window rather than an active incident.

Do this: Deploy the Windows update that addresses CVE-2026-20841 to all endpoints through your normal patch channel and prioritize systems where users routinely open text files from email or downloads.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-20841

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

Full tracking and change history for CVE-2026-20841

Published
2026-02-10
Last revised
2026-05-11
Changes tracked
1

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.

How to fix CVE-2026-20841

Apply the latest Microsoft security update for the affected product. Most environments deliver it automatically through Intune update rings, Windows Update for Business, Windows Autopatch, or WSUS; for a manual install, download from the Microsoft Update Catalog. The MSRC advisory lists the exact patched build per product.

Microsoft MSRC advisoryNVD detail

Affected products

Common questions about CVE-2026-20841

Is CVE-2026-20841 actively exploited?

It is not currently listed in the CISA Known Exploited Vulnerabilities catalog. That can change: unexploited CVEs regularly get weaponized months after disclosure, which is why patching on your normal cadence matters.

What fixes CVE-2026-20841?

Microsoft ships the fix in its security updates. Apply the latest cumulative or security update for the affected product through Windows Update, Intune, Windows Update for Business, or the Microsoft Update Catalog, and see the MSRC advisory below for the exact build.

Which products are affected by CVE-2026-20841?

Windows Notepad.

Can I ask my own AI about CVE-2026-20841?

Yes. This page includes a free, ready-to-paste AI prompt with CVE-2026-20841's key facts: severity, CVSS, CISA KEV status, and the affected products. Copy it into Claude, ChatGPT, or Copilot for a triage plan.

Authoritative references

CVE recordNVD detailMicrosoft MSRC

Every Microsoft CVE and the patches that fix it, ranked by real-world risk: the Microsoft Patch Tracker. The full searchable CVE reference: CVE and vulnerability management.

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Lexicon: the terms on this page
CVE
Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB
Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV
CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS
Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS
Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC
Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD
National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware
The vulnerability is linked to known ransomware activity.
Reference: Microsoft CVE and vulnerability management, the full CVE-to-patch lookup ranked by real-world risk, and the Microsoft patching guide, how Intune, Windows Autopatch, Defender, and Azure Update Manager fit together.
Data notice: this page, the feeds, and the API are provided as is, for informational purposes only, without warranty of any kind. Senserva, LLC does not guarantee the accuracy, completeness, or timeliness of third-party data (MSRC, NVD, CISA KEV, EPSS) and accepts no liability for actions taken based on it; verify against the authoritative vendor advisory before acting. Built daily with Senserva Trustworthy AI. All use of this data is subject to the Senserva EULA.