CVE-2023-40031

HIGH

Notepad++ < 8.5.6 - Heap-based Buffer Overflow in Utf8_16_Read::convert

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2023-40031. PoCs published by webraybtl.

AI-analyzed exploit summary This repository provides a technical analysis of CVE-2023-40031, a heap buffer overflow vulnerability in Notepad++'s Utf8_16_Read::convert function during UTF-16 to UTF-8 conversion. It includes details on the root cause, affected versions, and reproduction environment but lacks actual exploit code.

Description

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++.

Exploits (1)

nomisec WRITEUP 15 stars
by webraybtl · poc
https://github.com/webraybtl/CVE-2023-40031

This repository provides a technical analysis of CVE-2023-40031, a heap buffer overflow vulnerability in Notepad++'s Utf8_16_Read::convert function during UTF-16 to UTF-8 conversion. It includes details on the root cause, affected versions, and reproduction environment but lacks actual exploit code.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Theoretical
Target: Notepad++ <=8.5.6
No auth needed
Prerequisites: Vulnerable version of Notepad++ installed · Ability to deliver crafted input to the application
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (1)

Core 1
Core References
Exploit, Third Party Advisory x_refsource_confirm
https://securitylab.github.com/advisories/GHSL-2023-092_Notepad__/

Scores

CVSS v3 7.8
EPSS 0.0049
EPSS Percentile 38.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-122 CWE-120
Status published
Products (1)
notepad-plus-plus/notepad\+\+ < 8.5.6
Published Aug 25, 2023
Tracked Since Feb 18, 2026