Notepad++: Authenticode verification bypass allows modified updater execution
Published Sep 22, 2026 · Updated Oct 23, 2026
Original summary
Normalized public record · Updated Oct 23, 2026
Notepad++: Authenticode verification bypass allows modified updater execution
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
Notepad++ is a free and open-source source code editor. From 8.9.7 until 8.9.8, the Notepad++ updater and signature verification path can accept a modified GUP.exe file whose embedded certificate metadata remains present even though its Authenticode digest is invalid. An attacker who can replace or plant the updater-related file can cause Notepad++ to launch attacker-modified code when a user triggers the updater path, but the issue does not provide remote code execution by itself. This issue is fixed in version 8.9.8.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- 10%
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
- Security advisory ↗
- Patch commit ↗
- Source repository ↗
- https://notepad-plus-plus.org/news/v898-released ↗
Record history
Published Sep 22, 2026 · Last refreshed Oct 23, 2026