CVE-2023-40031 Notepad++ vulnerable to heap buffer write overflow in Utf8_16_Read::convert
A heap buffer overflow in Notepad++ allows arbitrary code execution, posing a risk to users opening malicious files.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2023-40031?
CVE-2023-40031 is a high-severity memory corruption vulnerability in notepad-plus-plus, published on 25 Aug 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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++.
Which versions are affected by CVE-2023-40031?
It affects 1 product.
Products include Notepad-Plus-Plus Notepad\+\+.
How do I fix CVE-2023-40031?
No fix has been published for CVE-2023-40031 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-40031 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-40031 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in notepad-plus-plus
- CVE-2025-15556 Notepad++ Download of Code Without Integrity Check
- CVE-2026-48778 Notepad++: Arbitrary Code Execution via config.xml commandLineInterpreter
- CVE-2026-48800 Notepad++: Arbitrary Code Execution via shortcuts.xml UserCommand Injection
- CVE-2026-52884 Notepad++: CVE-2026-48800 Bypass
- CVE-2023-47452 Privilege escalation in n/a