CVE-2025-15556
HIGHCISA KEVDescription
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 to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 67% of all known CVEs.
Remediation due: 2026-03-05
References
Related Vulnerabilities
Other CWE-494 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-5398 | High | 7.5 | 88% | - | Fix |
| CVE-2022-40799 | High | 8.8 | 32% | KEV | - |
| CVE-2026-3502 | High | 7.8 | 5.8% | KEV | Fix |
| CVE-2018-19234 | High | 8.8 | 3.3% | - | Fix |
| CVE-2016-6567 | Critical | 9.8 | 2.9% | - | - |
| CVE-2016-6564 | High | 8.1 | 2.7% | - | - |
Common questions
How do I fix CVE-2025-15556?
Upgrade notepad\+\+ to 8.8.9 or later.
Is CVE-2025-15556 being actively exploited?
Yes. CVE-2025-15556 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2026-03-05. Treat it as a priority whatever its CVSS score says.
How severe is CVE-2025-15556?
CVE-2025-15556 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2025-15556 affect?
Published advisories record a fix for notepad\+\+ (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2025-15556
Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-13.