CVE-2026-20841

HIGH

Windows Notepad App - Command Injection

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 16 public exploits for CVE-2026-20841. PoCs published by BTtea, patchpoint, XiaomingX.

AI-analyzed exploit summary The repository contains a README.md describing a potential RCE vulnerability in Windows notepad.exe but lacks actual exploit code or technical details. It references unclear exploitation steps via images.

Description

Improper neutralization of special elements used in a command ('command injection') in Windows Notepad App allows an unauthorized attacker to execute code locally.

Exploits (16)

nomisec WRITEUP 120 stars
by BTtea · poc
https://github.com/BTtea/CVE-2026-20841-PoC

The repository contains a README.md describing a potential RCE vulnerability in Windows notepad.exe but lacks actual exploit code or technical details. It references unclear exploitation steps via images.

Classification
Writeup 30%
Attack Type
Rce
Complexity
Theoretical
Reliability
Theoretical
Target: Windows notepad.exe < 11.2510
No auth needed
Prerequisites: Notepad Version < 11.2510
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP 11 stars
by patchpoint · poc
https://github.com/patchpoint/CVE-2026-20841

This repository provides a detailed analysis of CVE-2026-20841, a command injection vulnerability in Microsoft Notepad's markdown rendering feature. It includes a proof-of-concept (PoC) demonstrating how an attacker could exploit this vulnerability to achieve remote code execution (RCE) by tricking a user into clicking a malicious link.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Theoretical
Target: Microsoft Notepad versions 11.0.0 to 11.2510
No auth needed
Prerequisites: User interaction required · Victim must open a malicious Markdown file in Notepad · Victim must click a link while holding the Control button
devstral-2 · analyzed Feb 16, 2026 Full analysis →
github SUSPICIOUS 10 stars
by XiaomingX · pythonpoc
https://github.com/XiaomingX/data-cve-poc-py-v1/tree/main/2026/CVE-2026-20841

The repository provides vague references to a Windows Notepad RCE (CVE-2026-20841) but lacks functional exploit code. The PoC.md contains placeholder links (ms-appinstaller and file URIs) without context, and the README offers no technical details, only screenshots and a disclaimer about uncertainty.

Classification
Suspicious 80%
Attack Type
Rce
Complexity
Theoretical
Reliability
Theoretical
Target: Windows Notepad < 11.2510
No auth needed
Prerequisites: None specified
devstral-2 · analyzed Feb 27, 2026 Full analysis →
nomisec WORKING POC 2 stars
by atiilla · poc
https://github.com/atiilla/CVE-2026-20841

This repository contains a proof-of-concept exploit for CVE-2026-20841, a remote code execution vulnerability in Windows Notepad's markdown renderer. The exploit leverages unrestricted URL protocols in markdown links to trigger arbitrary protocol handlers, leading to RCE via file://, ms-appinstaller://, or local binary execution.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Windows Notepad (specific vulnerable builds)
No auth needed
Prerequisites: Attacker-controlled payload accessible via UNC path or web server · Victim interaction (clicking a link in Notepad)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 2 stars
by uky007 · poc
https://github.com/uky007/CVE-2026-20841_notepad_analysis

This repository contains a proof-of-concept exploit for CVE-2026-20841, a URI scheme validation bypass in Microsoft Store Notepad's Markdown preview feature. The exploit generates malicious Markdown files that leverage unfiltered URI schemes to execute arbitrary commands or install malicious packages.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Microsoft Store Notepad < 11.2510
No auth needed
Prerequisites: Windows 10/11 with vulnerable Notepad version · Markdown preview feature enabled · User interaction (clicking a link)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP 1 stars
by SecureWithUmer · poc
https://github.com/SecureWithUmer/CVE-2026-20841

This repository provides a writeup and proof-of-concept for CVE-2026-20841, a remote code execution vulnerability in Windows Notepad's markdown renderer. The flaw allows arbitrary protocol handlers to be triggered via clickable links, potentially leading to the execution of local binaries.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Windows Notepad (specific vulnerable builds)
No auth needed
Prerequisites: Vulnerable version of Windows Notepad · User interaction (clicking a malicious link)
MITRE ATT&CK
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP 1 stars
by dogukankurnaz · poc
https://github.com/dogukankurnaz/CVE-2026-20841-PoC

This repository provides a detailed writeup and proof-of-concept for CVE-2026-20841, a command injection vulnerability in the Windows Notepad app (Microsoft Store version) that allows remote code execution via malicious Markdown links.

Classification
Writeup 100%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Windows Notepad App (Microsoft Store version, builds prior to 11.2510)
No auth needed
Prerequisites: Victim must open a malicious Markdown file in the vulnerable Notepad app · Victim must click on a malicious link within the file
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 1 stars
by tangent65536 · poc
https://github.com/tangent65536/CVE-2026-20841

This PoC demonstrates a Windows Notepad RCE vulnerability (CVE-2026-20841) by generating a markdown file with a malicious `file:///` URL pointing to a WebDAV/SMB payload. The exploit leverages Notepad's markdown engine to bypass typical warning prompts for certain file extensions like `.py` or `.jar`.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Windows Notepad (unpatched version)
No auth needed
Prerequisites: WebDAV/SMB server hosting the payload · Target system with vulnerable Notepad version · User interaction to open the markdown file and click the link
devstral-2 · analyzed Feb 16, 2026 Full analysis →
github WORKING POC
by 0xBlackash · javascriptpoc
https://github.com/0xBlackash/CVE-2026-20841

This repository contains functional PoC code for CVE-2026-20841, a critical RCE vulnerability in Windows Notepad's Markdown processing. The scripts generate a malicious markdown file that exploits unsafe WebDAV link handling when opened in vulnerable Notepad versions.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Windows Notepad (UWP version with Markdown support)
No auth needed
Prerequisites: WebDAV server running on attacker-controlled host · Payload file accessible via WebDAV · Victim interaction (clicking link in Notepad)
devstral-2 · analyzed Jun 02, 2026 Full analysis →
github WORKING POC
by XZ1r0 · pythonpoc
https://github.com/XZ1r0/cve-2026-poc-collection/tree/main/other/CVE-2026-20841-PoC

The repository contains a functional proof-of-concept for CVE-2026-20841, demonstrating a remote code execution vulnerability in Windows Notepad.exe versions prior to 11.2510. The PoC leverages URI handlers to execute arbitrary commands via crafted links.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Windows Notepad.exe < 11.2510
No auth needed
Prerequisites: Windows system with vulnerable Notepad.exe version
devstral-2 · analyzed May 21, 2026 Full analysis →
nomisec SUSPICIOUS
by hamzamalik3461 · poc
https://github.com/hamzamalik3461/CVE-2026-20841

The repository claims to provide a PoC for CVE-2026-20841 but lacks actual exploit code, instead directing users to external downloads. The README is vague and focuses on marketing language rather than technical details.

Classification
Suspicious 90%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: Windows Notepad (markdown feature)
No auth needed
Prerequisites: Windows 10 or later · Notepad installed
devstral-2 · analyzed Feb 27, 2026 Full analysis →
nomisec SUSPICIOUS
by 404godd · poc
https://github.com/404godd/CVE-2026-20841-PoC

The repository lacks actual exploit code and instead directs users to download external files from GitHub releases. The README is vague and focuses on marketing language rather than technical details about CVE-2026-20841.

Classification
Suspicious 90%
Attack Type
Other
Complexity
Theoretical
Reliability
Theoretical
Target: unspecified
No auth needed
Prerequisites: none specified
devstral-2 · analyzed Feb 26, 2026 Full analysis →
nomisec SUSPICIOUS
by EleniChristopoulou · poc
https://github.com/EleniChristopoulou/PoC-CVE-2026-20841

The repository claims to be a PoC for CVE-2026-20841 but lacks actual exploit code, instead directing users to download an external executable from another repository. The description is vague and relies on social engineering tactics without technical details.

Classification
Suspicious 90%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: Windows Notepad < 11.2510
No auth needed
Prerequisites: User interaction to download and execute an external file
devstral-2 · analyzed Feb 17, 2026 Full analysis →
nomisec WRITEUP
by hackfaiz · poc
https://github.com/hackfaiz/CVE-2026-20841-PoC

The repository contains a README describing CVE-2026-20841, a command execution vulnerability in Microsoft Notepad triggered by crafted file input. No exploit code is provided, only a detailed writeup of the vulnerability.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Theoretical
Target: Microsoft Notepad (version unspecified)
No auth needed
Prerequisites: User interaction (opening a crafted file)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WRITEUP
by RajaUzairAbdullah · poc
https://github.com/RajaUzairAbdullah/CVE-2026-20841

This repository contains a writeup for CVE-2026-20841, claiming an RCE vulnerability in Windows notepad.exe version 11.2510.14.0. The provided steps involve saving and opening a file, but no actual exploit code or technical details are included.

Classification
Writeup 30%
Attack Type
Rce
Complexity
Theoretical
Reliability
Theoretical
Target: Windows notepad.exe 11.2510.14.0
No auth needed
Prerequisites: Windows notepad.exe version 11.2510.14.0
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (2)

Core 2

Scores

CVSS v3 7.8
EPSS 0.0018
EPSS Percentile 39.6%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-77
Status published
Products (3)
Microsoft/Windows Notepad 11.0.0 - 11.2512
Microsoft/Windows Notepad 11.0.0 - 11.2512.26.0
microsoft/windows_notepad < 11.2510
Published Feb 10, 2026
Tracked Since Feb 18, 2026