CVE-2025-15556
Notepad++ Download of Code Without Integrity Check Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 5 March 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 7.7 HIGHCVSS: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/M
- EPSS
- 1.75% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 12 February 2026 · due 5 March 2026
- Weakness
- CWE-494
- Affected
- notepad-plus-plus/notepad\+\+
- Source
- disclosure@vulncheck.com
EPSS 1.7% since 30 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. 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
References
- https://community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fixRelease Notes
- https://github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5abPatch
- https://github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdbPatch
- 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-verificationThird Party Advisory
- https://notepad-plus-plus.org//news//clarification-security-incident/Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.