High severity · published Aug 25, 2023
CVE-2023-40031
Notepad++ vulnerable to heap buffer write overflow in Utf8_16_Read::convert
7.8
CVSS
0.5%
EPSS
No
On KEV
Description
Notepad++ is a free and open-source source code editor. Versions 8.5.6 and prior are vulnerable to heap buffer write overflow in `Utf8_16_Read::convert`. This issue may lead to arbitrary code execution. As of time of publication, no known patches are available in existing versions of Notepad++.
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)0.5% · higher than 44% 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
<= 8.5.6 · source: vendor
NO
Notepad++ · Notepad-plus-plus
through 8.5.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-40031
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-40031
Exploit
https://securitylab.github.com/advisories/GHSL-2023-092_Notepad__/
More from notepad-plus-plus
7.5
CVE-2025-15556
Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification
8.6
CVE-2026-85279
Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value
8.1
CVE-2026-57233
Notepad++: Path Traversal (Zip Slip) in WinGup Plugin Extraction
7.8
CVE-2026-77605
Notepad++ “Run by system” executes *.txt.cmd when user selected *.txt (target confusion → command execution)
7.8
CVE-2026-86054
Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path