CVE-2025-15556
notepad-plus-plus
Published 3 Feb 2026 · updated 17 Jun 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 12 Feb 2026, with a remediation deadline of 5 Mar 2026 for US federal agencies.
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.
Description
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.
References
- community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix · Release Notes
- github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab · Patch
- github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb · Patch
- notepad-plus-plus.org/news/hijacked-incident-info-update/ · Patch, Vendor Advisory
- www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification · Third Party Advisory
- notepad-plus-plus.org//news//clarification-security-incident/ · Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556 · US Government Resource