Notepad++: Null pointer dereference in NPPM_SAVESESSION message handler causes crash (DoS)

Summary

CVECVE-2026-86056
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-22 18:17:24 UTC
Updated2026-09-23 18:28:25 UTC
DescriptionNotepad++ is a free and open-source source code editor. Prior to 8.9.8, the NPPM_SAVESESSION handler in PowerEditor/src/NppBigSwitch.cpp converts lParam to a sessionInfo pointer and dereferences its nbFile, files, and sessionFilePathName members without checking for null. A process running at the same or a higher Windows integrity level on the same desktop can send NPPM_SAVESESSION with a null lParam, immediately terminating Notepad++ and causing denial of service and loss of unsaved documents. This issue is fixed in version 8.9.8.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.001620000 probability, percentile 0.057960000 (date 2026-09-23)

Problem Types: CWE-476 | CWE-476 CWE-476: NULL Pointer Dereference


VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Notepad-plus-plus Notepad-plus-plus affected < 8.9.8 Not specified

References

ReferenceSourceLinkTags
notepad-plus-plus.org/news/v898-released [email protected] notepad-plus-plus.org
github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-... [email protected] github.com
github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8 [email protected] github.com
github.com/notepad-plus-plus/notepad-plus-plus/commit/8b33f52e7aa488b122... [email protected] github.com
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