CVE-2026-85279
Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.6
Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.
- Record
CVE-2026-85279- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
EUVDEUVD-2026-84570
8.6
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.
- Record
EUVD-2026-84570- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
8.6
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.
- Record
CVE-2026-85279- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
OSV
8.6
Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in PluginsManager::loadPluginFromPath in PowerEditor/src/MISC/PluginsManager/PluginsManager.cpp because the plugin-supplied GetLexerCount() result controls a loop that writes to containers[30] without enforcing NB_MAX_EXTERNAL_LANG. A malicious or compromised plugin that reports more than 30 lexers can write beyond the stack array and corrupt control data, which can permit arbitrary code execution in the Notepad++ process context. This issue is fixed in version 8.9.8.
- Record
CVE-2026-85279- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-85279 is a high vulnerability (CVSS 8.6) in Notepad-plus-plus, published September 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 13th percentile. No source names a fixed version.
References
github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-h2wq-6x75-h8q2
github.com/notepad-plus-plus/notepad-plus-plus/commit/70b88f95311d88523cde6be1b1ec938aa48c24bc
github.com/notepad-plus-plus/notepad-plus-plus/commit/f1e1c71b090d69ca0f0175ab73895da41db67a16
github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8
notepad-plus-plus.org/news/v898-released
github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85279.json
nvd.nist.gov/vuln/detail/CVE-2026-85279