CVE-2026-86054

Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path

Published: Sep 22, 2026Updated: Sep 23, 2026 Sources: CVE List NVDCWE-121

7.8HIGH

Description

Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in NppParameters::writeSession in PowerEditor/src/Parameters.cpp because it copies a session path derived from -settingsDir= into backupPathName[MAX_PATH] with unbounded wcscpy and appends SESSION_BACKUP_EXT with unbounded wcscat. A sufficiently long settings directory causes the backup suffix to exceed the fixed stack buffer when Notepad++ saves the session, and the protected release build terminates through its stack canary, causing denial of service. This issue is fixed in version 8.9.8.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:LAttack Vector

Local

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:UScope

Unchanged

Impact

C:HConfidentiality

High

I:HIntegrity

High

A:HAvailability

High

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Weaknesses

CWE-121

Affected Products

notepad-plus-plus

commercialaka notepad+ plus, notepad++, notepad plus plus

notepad-plus-plusOn-prem

Consumer Software / productivity

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique

Privilege Escalation

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References

https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx

github.com

https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf

github.com

https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8

github.com

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