CVE-2025-15556
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNotepad++ 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe WinGUp updater in Notepad++ versions before 8.8.9 lacks cryptographic verification of downloaded update metadata and installer packages. When an attacker performs a man-in-the-middle attack on the update channel, they can deliver a malicious installer that the updater will execute with the current user's privileges, achieving arbitrary code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 8.8.9CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Notepad++ versionOpen Notepad++ and go to Help > About Notepad++, or right-click notepad++.exe and select Properties > Details to view the Product versionAffected if Version is displayed as lower than 8.8.9 (e.g., 8.8.8, 8.7.x, etc.)
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Identify WinGUp updater usageLook for the WinGUp updater component in the Notepad++ installation directory (commonly in the updater folder or as part of the Notepad++ package)Affected if WinGUp updater files are present in the Notepad++ installation directory and the version is below 8.8.9
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Verify update check mechanismAttempt to trigger a manual update check through Notepad++ menu (Help > Check for Update) or inspect the updater configuration files in the installation directoryAffected if Update check executes through WinGUp and the installed version is prior to 8.8.9, meaning cryptographic verification is not performed on downloaded metadata/installers
User is affected if Notepad++ version is below 8.8.9 AND the WinGUp updater is used to fetch updates, allowing potential man-in-the-middle injection of malicious installers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped8.8.9
Upgrade to Notepad++ 8.8.9 or later which implements proper cryptographic signature verification for updates. Until then, avoid using the automatic update feature and download updates manually from trusted sources.
Notepad++ 8.8.9
- Navigate to the official Notepad++ website (notepad-plus-plus.org) and download version 8.8.9 or later
- Verify the downloaded installer file before running it
- Run the installer and follow the prompts to complete the upgrade
- After installation, verify the installed version by checking Help > About Notepad++
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-15556 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-15556 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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