CVE-2026-48800: Notepad++ OS command injection in UserDefinedCommands

CVE-2026-48800 · Severity: high · CVSS 7.8 · Published 2026-06-26

Notepad++ is a popular open-source text and code editor. A vulnerability in how the application handles user-defined commands allows an attacker to inject malicious commands into the program's 'Run' menu by modifying a configuration file. If a user is tricked into clicking the malicious menu item, the attacker can execute arbitrary code on the system, potentially leading to full system compromise or persistent access.

Quick answers

Is CVE-2026-48800 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48800 being exploited in the wild.
How severe is CVE-2026-48800?
High severity, with a CVSS score of 7.8, published 26 June 2026.
Which products and versions are affected?
Notepad++ Notepad++ < 8.9.6.1.
Is there a fix for CVE-2026-48800?
A patch was published on 2026-05-26: Fix committed to repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48800 attacked?
It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-48800?
Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An OS command injection vulnerability exists in Notepad++ prior to version 8.9.6.1. The application reads the <Command> tag within <UserDefinedCommands> from the shortcuts.xml file using NppXml::value() and stores it in UserCommand._cmd without validation. When a user selects the corresponding entry in the 'Run' menu, the application calls ShellExecute with the attacker-controlled string. Attackers can exploit this by directly writing to the configuration file in the user's APPDATA directory or by using the -settingsDir command-line argument to point to a malicious directory. This can be used as a persistence mechanism, as the injected command appears as a legitimate menu item. The issue is fixed in version 8.9.6.1 by adding user confirmation dialogs.

Affected products

  • Notepad++ Notepad++ < 8.9.6.1

Timeline

  • 2026-05-26: patched: Fix committed to repository
  • 2026-05-27: advisory: GitHub Security Advisory published
  • 2026-06-26: disclosed: CVE published to NVD

References

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