CVE-2025-15556

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.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 7.7CVSS 4.0, Highfrom the CNA (VulnCheck)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

What 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.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 9 Dec 2025 Vulnerability is publicly disclosed
2. 2 Feb 2026 Announcement of exploitation in the wild
3. 3 Feb 2026 Published
4. 12 Feb 2026 CVE-2025-15556 added to CISA KEV
5. 12 Feb 2026 Added to the CISA KEV catalogue

Weakness

• CWE-494

References

• community.notepad-plus-plus.orgrelease-notespatch
• notepad-plus-plus.orgvendor-advisory
• github.compatch
• github.compatch
• www.vulncheck.comthird-party-advisory