CVE-2026-54758

Notepad++: Stack Buffer Overflow in expandNppEnvironmentStrs

Published Aug 17, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the expandNppEnvironmentStrs function in PowerEditor/src/WinControls/StaticDialog/RunDlg/RunDlg.cpp copies a Notepad++ variable name between $( and ) into the fixed-size wchar_t str[MAX_PATH] stack buffer without bounding the m loop index, allowing a name of 260 or more characters to corrupt adjacent stack data, terminate the process through __report_gsfailure, and potentially execute code. This issue is fixed in version 8.9.7.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Notepad-plus-plus
Notepad-plus-plus notepad++
Vendors & Products Notepad-plus-plus
Notepad-plus-plus notepad++
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the expandNppEnvironmentStrs function in PowerEditor/src/WinControls/StaticDialog/RunDlg/RunDlg.cpp copies a Notepad++ variable name between $( and ) into the fixed-size wchar_t str[MAX_PATH] stack buffer without bounding the m loop index, allowing a name of 260 or more characters to corrupt adjacent stack data, terminate the process through __report_gsfailure, and potentially execute code. This issue is fixed in version 8.9.7.
Title Notepad++: Stack Buffer Overflow in expandNppEnvironmentStrs
Weaknesses CWE-121
CWE-787
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 17, 2026, 10:01 PM
Reserved
Jun 15, 2026, 11:12 PM
Status
Awaiting Analysis
Published
Aug 17, 2026, 8:16 PM
Modified
Sep 9, 2026, 9:11 PM