CVEs / CVE-2025-15556
CVE-2025-15556: Notepad++ Download of Code Without Integrity Check Vulnerability
- Known exploited in the CISA KEV catalog since 12 Feb 2026
- high 7.5 CVSS 3.1 (NVD)
- EPSS 1.74% chance of exploitation in the next 30 days, higher than 77% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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 and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| notepad-plus-plus notepad-plus-plus | before 8.8.9 | 8.8.9 |
Exploitation
| In CISA KEV since | 12 Feb 2026 |
|---|---|
| Due date for US federal agencies | 5 Mar 2026 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
Severity
| CVSS 3.1 | 7.5 highCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-494 |
References
- CVE-2025-15556 on NVD
- CVE-2025-15556 in the CISA KEV catalog
- https://notepad-plus-plus.org/news/clarification-security-incident/ (cited by CISA)
- https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix (cited by CISA)
- CVE-2025-15556 on OSV
- https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix Release Notes
- https://github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab Patch
- https://github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb Patch
- https://notepad-plus-plus.org/news/hijacked-incident-info-update/ Patch, Vendor Advisory
- https://www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification Third Party Advisory
- https://notepad-plus-plus.org//news//clarification-security-incident/ Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.