Notepad-Plus-Plus: >> Notepad++ >> 1.5 Security Vulnerabilities
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appears to process COPYDATASTRUCT.lpData as an unbounded NUL-terminated wchar_t* instead of enforcing COPYDATASTRUCT.cbData. This vulnerability is fixed in 8.9.6.1.
CVSS Score
5.0
EPSS Score
0.003
Published
2026-06-26
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, the <GUIConfig name="commandLineInterpreter"> tag in config.xml is read by NppXml::value() (Parameters.cpp:6430) and stored in _nppGUI._commandLineInterpreter without any validation, whitelist, or digital signature check. When the user triggers IDM_FILE_OPEN_CMD (File → Open Containing Folder → cmd), NppCommands.cpp:228 creates a Command object with this value and calls run(), which invokes ShellExecute (RunDlg.cpp:221) with the attacker-controlled string as the executable path. This vulnerability is fixed in 8.9.6.1.
CVSS Score
7.8
EPSS Score
0.013
Published
2026-06-26
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, the <Command> tag text content inside <UserDefinedCommands> in shortcuts.xml is read by NppXml::value(aNode) (Parameters.cpp:3658) in the feedUserCmds() function and stored in UserCommand._cmd without any validation. When the user clicks the corresponding entry in the Run menu, NppCommands.cpp:4264 creates a Command object with string2wstring(ucmd.getCmd()) and calls run(), which invokes ShellExecute (RunDlg.cpp:221) with the attacker-controlled string as the executable path. The injected command appears as a normal menu item in the Run menu, making it a viable persistence mechanism. This vulnerability is fixed in 8.9.6.1.
CVSS Score
7.8
EPSS Score
0.004
Published
2026-06-26
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.4, NppCommands.cpp checks the HMAC of the on-disk shortcuts.xml at the moment a user command fires (Time-of-Check). However, the command payload is taken from the in-memory _userCommands vector, which is populated at application startup and never re-synchronized with the on-disk file (Time-of-Use). Swapping shortcuts.xml between startup and command execution causes the HMAC check to validate a clean file while a malicious command runs. An attacker with write access to shortcuts.xml places a malicious version on disk before launch, then immediately restores the legitimate file. The HMAC check at execution time validates the restored legitimate file (check passes), while the malicious payload executes from memory. This vulnerability is fixed in 8.9.6.4.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-06-26
Notepad++ is a free and open-source source code editor. An Unsafe Search Path vulnerability (CWE-426) exists in versions prior to 8.9.2 when launching Windows Explorer without an absolute executable path. This may allow execution of a malicious explorer.exe if an attacker can control the process working directory. Under certain conditions, this could lead to arbitrary code execution in the context of the running application. Version 8.9.2 patches the issue.
CVSS Score
7.3
EPSS Score
0.002
Published
2026-02-19
CVE-2025-15556
Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges of the user.
Known exploited
CVSS Score
7.7
EPSS Score
0.013
Published
2026-02-03
A vulnerability classified as problematic was found in NotePad++ up to 8.1. Affected by this vulnerability is an unknown functionality of the file dbghelp.exe. The manipulation leads to uncontrolled search path. An attack has to be approached locally. The identifier VDB-246421 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
CVSS Score
5.3
EPSS Score
0.003
Published
2023-11-30
Notepad++ is a free and open-source source code editor. Versions 8.5.6 and prior are vulnerable to global buffer read overflow in `nsCodingStateMachine::NextStater`. The exploitability of this issue is not clear. Potentially, it may be used to leak internal memory allocation information. As of time of publication, no known patches are available in existing versions of Notepad++.
CVSS Score
5.5
EPSS Score
0.005
Published
2023-08-25
Notepad++ is a free and open-source source code editor. Versions 8.5.6 and prior are vulnerable to heap buffer read overflow in `FileManager::detectLanguageFromTextBegining `. The exploitability of this issue is not clear. Potentially, it may be used to leak internal memory allocation information. As of time of publication, no known patches are available in existing versions of Notepad++.
CVSS Score
5.5
EPSS Score
0.005
Published
2023-08-25
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 Score
7.8
EPSS Score
0.005
Published
2023-08-25
Page 1