CVE entry · CVE-2025-15556
CVE-2025-15556: Notepad++ Download of Code Without Integrity Check Vulnerability
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.
- Actively exploited: added to CISA’s KEV catalog on February 12, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: March 5, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes Notepad++, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.
References
- Vendor advisory or reference cited by CISA (notepad-plus-plus.org)
- Vendor advisory or reference cited by CISA (community.notepad-plus-plus.org)
- NVD entry (NIST)
- CISA KEV catalog