Notepad++ Download of Code Without Integrity Check Vulnerability
notepad-plus-plus — notepad-plus-plus
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.
7.7
1.7%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- None
- Privileges required
- None
- User interaction
- Passive
- Confidentiality (Vulnerable System)
- High
- Integrity (Vulnerable System)
- High
- Availability (Vulnerable System)
- High
- Confidentiality (Subsequent System)
- None
- Integrity (Subsequent System)
- None
- Availability (Subsequent System)
- None
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Published
- Feb 3, 2026
- Modified
- Mar 5, 2026
- Added to KEV
- Feb 12, 2026
- Federal patch due
- Mar 5, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2025-15556, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2025-15556 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2025-15556?
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.
How severe is CVE-2025-15556?
CVE-2025-15556 has a CVSS base score of 7.7 out of 10 (CVSS 4.0).
Is CVE-2025-15556 actively exploited in the wild?
Yes. CVE-2025-15556 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Feb 12, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2025-15556?
1.7% - meaning FIRST.org's EPSS model estimates a 1.7% probability this vulnerability will be exploited in the wild within 30 days (76% percentile among all scored CVEs).
What type of vulnerability is CVE-2025-15556?
CVE-2025-15556 is classified under CWE-494 (CWE-494 Download of Code Without Integrity Check).
Cross-checked against
Impactr finds and proves whether CVE-2025-15556 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.