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

CISA Known Exploited Vulnerabilities

Name

Notepad++ Download of Code Without Integrity Check Vulnerability

Vendor

Notepad++

Product

Notepad++

Added to the catalog

2026-02-12

Due date for US federal agencies

2026-03-05

Weaknesses

CWE-494

Catalog version

2026.10.30

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.

Required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

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

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2026-02-03T01:15:57.757

Last modified

2026-06-17T08:38:01.047

Weaknesses

CWE-494

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.

References

• 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)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:22.836Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2025-15556

CVE record

Title (CNA)

Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification

Assigner

VulnCheck

State

PUBLISHED

Published

2026-02-03T00:50:29.516Z

Updated

2026-03-05T01:29:51.538Z

Problem types

CWE-494 Download of Code Without Integrity Check

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.

References

• https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix
• https://notepad-plus-plus.org/news/hijacked-incident-info-update/
• https://github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab
• https://github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb
• https://www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification

Read on 2026-11-03T02:14:52.729Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2025/15xxx/CVE-2025-15556.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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