Vulnerability details

Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges of the user.

• https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix release-notespatch
• https://notepad-plus-plus.org/news/hijacked-incident-info-update/ vendor-advisory
• https://github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab patch
• https://github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb patch
• https://www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification third-party-advisory
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556 government-resource
• https://notepad-plus-plus.org//news//clarification-security-incident/ third-party-advisory