CVE-2026-42214: DAIL8859 Notepad Next

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

Notepad Next is a cross-platform, reimplementation of Notepad++. Prior to version 0.14, NotepadNext's detectLanguageFromExtension() function interpolates a file's extension directly into a Lua script without sanitization. An attacker can craft a filename whose extension contains Lua code, which executes automatically when the victim opens the file in NotepadNext. Because luaL_openlibs() is called unconditionally, the full os, io, and package libraries are available to the injected code, enabling arbitrary command execution. This issue has been patched in version 0.14.

Affected products

• DAIL8859 Notepad Next: before 0.14 (fixed in 0.14)

Published 2026-05-07. Last modified 2026-06-17.