CVE-2025-15556
Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification
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.
- Record
CVE-2025-15556- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-494
- Updated
- 2026-11-02
EUVDEUVD-2025-206661
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.
- Record
EUVD-2025-206661- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cqx4-h5ph-3xj9
Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity...
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.
- Record
GHSA-cqx4-h5ph-3xj9- CVSS 4.0
- 7.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-494
- Updated
- 2026-11-02
CISA KEV No score
Notepad++ Download of Code Without Integrity Check Vulnerability
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.
- Record
CVE-2025-15556- Weakness
- CWE-494
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-15556- CVSS 4.0
- 7.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-494
- Updated
- 2026-11-02
OSV
Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification
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.
- Record
CVE-2025-15556- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-494
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | renat0z3r0/notepadpp-supply-chain-iocs | 2026-02-09 |
| PoC in GitHub | George0Papasotiriou/CVE-2025-15556-Notepad-WinGUp-Updater-RCE | 2026-02-10 |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation, exploits | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-15556 is a high vulnerability (CVSS 7.7) in Notepad++, published February 3, 2026. CISA lists it as known to be exploited, since February 12, 2026. EUVD reports exploitation since February 12, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.75%, the 77th percentile. No source names a fixed version.
References
community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix
notepad-plus-plus.org/news/hijacked-incident-info-update
github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab
vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556