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TI-2026-58566 Aliases CVE-2026-85279

Notepad++: Stack Buffer Overflow in Plugin Lexer Loading via Unchecked GetLexerCount() Return Value

Priority HIGH 72CWE-121Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00224 13th percentileScored 2026-11-07
Fix Fixed notepad-plus-plus (notepad-plus-plus): 8.9.8

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
notepad-plus-plusnotepad-plus-plusbefore 8.9.88.9.8Patch availableCNA
  • notepad-plus-plus Vendornotepad-plus-plus Affected before 8.9.8 Fixed in 8.9.8 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:notepad-plus-plus:notepad\+\+:*:*:*:*:*:*:*:*——notepad-plus-plus
  • cpe:2.3:a:notepad-plus-plus:notepad\+\+:*:*:*:*:*:*:*:* Versions — — ·notepad-plus-plus

Remediation

  • Fix · CNA notepad-plus-plus (notepad-plus-plus) Fixed in 8.9.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-85279

References

Other 5

  • TI-2025-14195 Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification KEVCVSS 4.0HIGH 7.7
  • TI-2026-58869 Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path CVSS 3.1HIGH 7.8
  • TI-2026-54091 Notepad++ “Run by system” executes *.txt.cmd when user selected *.txt (target confusion → command execution) CVSS 3.1HIGH 7.8
  • TI-2026-36070 Notepad++: Arbitrary Code Execution via shortcuts.xml UserCommand Injection CVSS 3.1HIGH 7.8
  • TI-2026-36048 Notepad++: Arbitrary Code Execution via config.xml commandLineInterpreter CVSS 3.1HIGH 7.8
  • TI-2026-04836 Stack-Based Buffer Overflow in Notepad++ File Drop Handler leads to DoS CVSS 3.1HIGH 7.8
See all 31 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences