What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2026-02-12
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-03 · updated 2026-06-17
• Weakness: CWE-494

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.

Affected products

• Notepad++: before 8.8.9 — fixed in 8.8.9

How to fix

Upgrade to a fixed version: Notepad++ 8.8.9. Check the vendor advisory for mitigations.

References

• https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix
• https://github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab
• https://github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb
• https://notepad-plus-plus.org/news/hijacked-incident-info-update/
• https://www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification
• https://notepad-plus-plus.org//news//clarification-security-incident/
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556

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