Notepad++ Download of Code Without Integrity Check
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA deadline 2026-03-05 · passed 6 months ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Notepad++ Notepad++. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-494.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 6 months ago
Sources
- NVD entry for CVE-2025-15556 nvd.nist.gov/vuln/detail/CVE-2025-15556
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- notepad-plus-plus.org notepad-plus-plus.org/news/clarification-security-incident/
- community.notepad-plus-plus.org community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2025-15556