CVE-2025-15556: Notepad++ Download of Code Without Integrity Check Vulnerability

Added to the CISA Known Exploited Vulnerabilities catalog on 12 Feb 2026. Vendor: Notepad++. Product: Notepad++.

Notepad++ when using the WinGUp updater, contains a download of code without integrity check vulnerability that could allow an attacker to intercept or redirect update traffic to download and execute an attacker-controlled installer. This could lead to arbitrary code execution with the privileges of the user.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (due 05 Mar 2026)