CVE-2026-54758
Notepad++: Stack Buffer Overflow in expandNppEnvironmentStrs
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.
INFO
Published Date :
Aug. 17, 2026, 8:16 p.m.
Last Modified :
Aug. 17, 2026, 10:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update Notepad++ to version 8.9.7 or later.
- Install security patches for Notepad++.
- Apply vendor-supplied updates immediately.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54758.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54758 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54758
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54758 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54758 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-54758', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-17T21:59:14.088744Z'} -
New CVE Received by [email protected]
Aug. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'notepad-plus-plus', 'product': 'notepad-plus-plus', 'versions': [{'status': 'affected', 'version': '< 8.9.7'}]}] 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. Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CWE CWE-121 Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/commit/0a9527e9f7140a2323e25d14e362b46ee0efc3db Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.7 Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-gv94-327x-2gc5