Vulnerability Intelligence Report
Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value
CVE-2026-85279
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.
No Active Exploit Signals
CVSS Base Score
8.6
HIGH
Exploitability:1.9
Impact Score:6.1
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
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SSVC Action
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Weaknesses (CWE)
CWE-121 ↗CWE-121: Stack-based Buffer Overflow
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| notepad-plus-plus | notepad-plus-plus | < 8.9.8 (affected) |
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GitHub, Inc. · Vendor · USA |
| Reserved | 2026-09-03T16:37:49 |
| Published | 2026-09-22T17:08:42 |
| Last Updated | 2026-09-22T18:27:51 |
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