CVE-2026-42214 Improper Control of Generation of Code ('Code Injection') in dail8859/NotepadNext
Attackers can execute arbitrary code by crafting filenames with malicious Lua extensions, affecting users of Notepad Next.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-42214?
CVE-2026-42214 is a high-severity code injection vulnerability in dail8859 NotepadNext, published on 7 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-94
Which versions are affected by CVE-2026-42214?
It affects 1 product.
Products include Dail8859 Notepad Next.
How do I fix CVE-2026-42214?
No fix has been published for CVE-2026-42214 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-42214 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42214 exists.
Sources
Also known as GHSA-m5fq-c9x5-w54g.