Security Resilience

CVE-2023-40166

Memory Safety in Notepad-Plus-Plus Notepad\+\+ ≤ 8.5.6

Public PoCMemory Safety
Published
25 August 2023
Modified
21 November 2024
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0041 34th percentile
Risk Priority 43 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-40166 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Notepad-Plus-Plus Notepad\+\+. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked at the 34th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

Notepad++ is a free and open-source source code editor. Versions 8.5.6 and prior are vulnerable to heap buffer read overflow in `FileManager::detectLanguageFromTextBegining `. The exploitability of this issue is not clear. Potentially, it may be used to leak internal memory…

more

allocation information. As of time of publication, no known patches are available in existing versions of Notepad++.

CWE(s)
CWE-120CWE-122

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-40031Same product: Notepad-Plus-Plus Notepad\+\+
CVE-2023-40036Same product: Notepad-Plus-Plus Notepad\+\+
CVE-2023-40164Same product: Notepad-Plus-Plus Notepad\+\+
CVE-2024-56805Shared CWE-120, CWE-122
CVE-2024-32763Shared CWE-120, CWE-122
CVE-2026-42536Shared CWE-120, CWE-122
CVE-2026-4177Shared CWE-120, CWE-122
CVE-2026-3082Shared CWE-120, CWE-122
CVE-2024-25115Shared CWE-120, CWE-122
CVE-2024-0156Shared CWE-120, CWE-122

Affected Assets

notepad-plus-plus
notepad\+\+
≤ 8.5.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.1
  • V1.4.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-01 partial match
blocks

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
blocks

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

PR.PS-06 partial match
blocks

Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References