Exploited vulnerability · CISA KEV

Is CVE-2025-15556 exploited? Yes: in CISA KEV since 12 Feb 2026

Gociux · Notepad++ · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2025-15556, Notepad++ Download of Code Without Integrity Check Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 12 Feb 2026, 9 days after it was published. It affects Notepad++. If you run it, CISA's required action is: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

What it is

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.

What to do

1. Check whether you run it. Look for Notepad++ in your asset inventory, including appliances and cloud images. Stack check lists every exploited Notepad++ CVE at once.
2. Apply the fix. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 3 Feb 2026.
4. Get told next time. Email alerts when CISA adds a CVE for Notepad++.

References

• notepad-plus-plus.org/news/clarification-security-incident/
• community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix
• nvd.nist.gov/vuln/detail/CVE-2025-15556

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in February 2026 · act-now radar.