Windows Notepad Remote Code Execution Vulnerability: 3 Key Takeaways
- CVSS 8.8 Command Injection Vulnerability (CVE-2026-20841) Discovered
- Remote Code Execution via Malicious Markdown File Link Click
- Fixed in February Patch Tuesday
Notepad Hacked with a Single Markdown Link
Microsoft has patched a Remote Code Execution (RCE) vulnerability in Windows Notepad. It’s registered as CVE-2026-20841 and has a CVSS score of 8.8, a ‘High’ severity rating.[CVE Feed]
The root cause is a command injection (CWE-77). Opening a manipulated Markdown file and clicking a malicious link allows Notepad to process external protocols without proper validation. This could lead to fetching remote files and executing arbitrary commands.[CybersecurityNews]
Only Affects Store Version of Notepad
This vulnerability targets the modern Notepad versions 11.0.0~11.2510 distributed through the Microsoft Store. The classic notepad.exe is not affected because it lacks Markdown functionality.[BleepingComputer]
The attack complexity is low, and no special privileges are required. Just open the file and click the link, and you’re done.
Update Now, It’s the Only Answer
The fix was released on February 10, 2026, as part of Patch Tuesday. A total of 58 vulnerabilities were patched this time, including 6 zero-days.[Zero Day Initiative]
While there are no known cases of active exploitation yet, PoC code has been released. Update Notepad to the latest version from the Store ASAP. Enabling automatic updates is a good idea.
It’s easy to underestimate a text editor, but as it evolves into a modern app, its attack surface expands. Hope this helps!
Frequently Asked Questions (FAQ)
Q: Is the classic Notepad affected?
A: This vulnerability only affects the modern Notepad distributed through the Store. The classic notepad.exe is not affected because it doesn’t have Markdown rendering capabilities. Still, it’s always a good idea to keep your Windows security updates up to date.
Q: How serious is a CVSS score of 8.8?
A: It’s a high (High) severity rating, with 8.8 out of 10. The attack difficulty is low, making it relatively easy to exploit, but it requires user interaction (opening a file and clicking a link), so it’s not automatically self-propagating.
Q: Are there any actions I can take besides patching?
A: Updating Notepad to the latest version from the Store is the most important thing. Enable automatic app updates and avoid opening Markdown files from untrusted sources.
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References
- CVE-2026-20841 Detail – CVE Feed (2026-02-10)
- Windows Notepad RCE Vulnerability – CybersecurityNews (2026-02-10)
- Microsoft February 2026 Patch Tuesday – BleepingComputer (2026-02-10)
- February 2026 Security Update Review – Zero Day Initiative (2026-02-10)