CVE-2026-57233: Notepad-Plus-Plus

High severity, CVSS 8.1. EPSS: 0.5% chance of exploitation in the next 30 days.

Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the WinGup decompress function joins untrusted ZIP entry names to unzipDestTo without canonical containment validation, allowing an entry such as ../mimeTools/mimeTools.dll to overwrite a DLL in a sibling plugin directory and execute attacker-controlled code when Notepad++ next loads that plugin. This issue is fixed in version 8.9.7.

Affected products

• Notepad-Plus-Plus Notepad-Plus-Plus: before 8.9.7 (fixed in 8.9.7)

Published 2026-08-17. Last modified 2026-09-09.