CVE-2025-15556 — Notepad++ Download of Code Without Integrity Check Vulnerability

Overview

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.

Vulnerability details

CVE ID

CVE-2025-15556

Vulnerability

Notepad++ Download of Code Without Integrity Check Vulnerability

Vendor

Notepad++

Affected products

Notepad++: Notepad++

Severity

HIGH

Exploitation status

Actively exploited in the wild (CISA KEV)

EPSS score

1.3% probability of exploitation in 30 days · 66th percentile

Published

2026-02-12

Remediation guidance

CVE-2025-15556 is in CISA's Known Exploited Vulnerabilities (KEV) catalog — U.S. federal civilian agencies are required to remediate it under Binding Operational Directive 22-01. Treat it as a priority for every environment.

Apply the vendor's official security update for Notepad++ the affected product as soon as possible. Where a patch is unavailable, apply vendor mitigations or isolate/segment exposed systems.

FIRST EPSS estimates a 1.3% probability that CVE-2025-15556 will be exploited within the next 30 days (66th percentile of all CVEs) — useful for risk-based patch sequencing.

Hunt for indicators of compromise tied to this vulnerability and confirm logging/EDR coverage on affected assets.

Authoritative references

• NVD — National Vulnerability Database
• MITRE CVE Record
• CISA Known Exploited Vulnerabilities Catalog
• FIRST EPSS — Exploit Prediction Scoring