High severity · published Aug 17, 2026
CVE-2026-54758
Notepad++: Stack Buffer Overflow in expandNppEnvironmentStrs
7.8
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
notepad-plus-plus · notepad-plus-plus
< 8.9.7 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54758
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54758
github.com
https://github.com/notepad-plus-plus/notepad-plus-plus/commit/0a9527e9f7140a2323e25d14e362b46ee0efc3db
github.com
https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.7
github.com
https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-gv94-327x-2gc5
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