High · published September 22, 2026
Notepad++ is a free and open-source source code editor. From 8.9.7 until 8.9.8, the Notepad++ updater and signature verification path can accept a modified GUP.exe file whose embedded certificate metadata remains present even though its Authenticode digest is invalid. An attacker who can replace or plant the updater-related file can cause Notepad++ to launch attacker-modified code when a user triggers the updater path, but the issue does not provide remote code execution by itself. This issue is fixed in version 8.9.8.