Code execution via unchecked plugin lexer count
Published Sep 22, 2026 · Updated Sep 22, 2026
Stack buffer overflow in Notepad++ before 8.9.8 allows local users to execute code by loading a malicious lexer plugin. PluginsManager::loadPluginFromPath trusts the plugin-supplied GetLexerCount result as a loop bound and writes past a 30-element stack array. Exploitation requires Notepad++ to load a malicious or compromised native plugin, after which the overflow can corrupt control data in the editor process.
Summary
What happened
Stack buffer overflow in Notepad++ before 8.9.8 allows local users to execute code by loading a malicious lexer plugin. PluginsManager::loadPluginFromPath trusts the plugin-supplied GetLexerCount result as a loop bound and writes past a 30-element stack array. Exploitation requires Notepad++ to load a malicious or compromised native plugin, after which the overflow can corrupt control data in the editor process.
The record
- CVE
- CVE-2026-85279
- Published
- Sep 22, 2026
- Updated
- Sep 22, 2026
- Vendor
- Notepad++
- Product
- Notepad++
- Classifications
- T1129
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 22, 2026CVE publishedPublication date reported by the CVE source.
- Sep 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 8.9.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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