CVE-2026-85279: Notepad-Plus-Plus

High severity, CVSS 8.6. EPSS: 0.2% chance of exploitation in the next 30 days.

Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.

Affected products

• Notepad-Plus-Plus Notepad-Plus-Plus: before 8.9.8 (fixed in 8.9.8)

Published 2026-09-22. Last modified 2026-09-23.