Known exploited vulnerability
CVE-2025-15556
The short answer
CVE-2025-15556 affects notepad-plus-plus notepad-plus-plus and is rated high (CVSS 7.7). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-02-12: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
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.
Weakness: CWE-494.
Severity
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
Exploited (CISA KEV)
Yes, since Feb 12, 2026
Federal due date Mar 5, 2026
EPSS, next 30 days
1.7%
Higher than 78% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- None
- Privileges required
- None
- User interaction
- Passive
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected products
notepad-plus-plus. NVD's record lists the exact affected versions.
References
- community.notepad-plus-plus.org/topic/27298/notepad-v8-8-9-vulnerability-fix Release Notes
- github.com/notepad-plus-plus/notepad-plus-plus/commit/bcf2aa68ef414338d717e20e059459570ed6c5ab Patch
- github.com/notepad-plus-plus/wingup/commit/ce0037549995ed0396cc363544d14b3425614fdb Patch
- notepad-plus-plus.org/news/hijacked-incident-info-update/ PatchVendor Advisory
- www.vulncheck.com/advisories/notepad-plus-plus-wingup-updater-lacks-update-integrity-verification Third Party Advisory
- notepad-plus-plus.org//news//clarification-security-incident/ Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-15556 US Government Resource
Questions
Is CVE-2025-15556 being exploited?
Yes. CISA added CVE-2025-15556 to its Known Exploited Vulnerabilities catalog on 2026-02-12, with a federal remediation due date of 2026-03-05.
How do I fix CVE-2025-15556?
CISA's 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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