Notepad++ heap buffer read overflow in FileManager::detectLanguageFromTextBegining

published 2023-08-25 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-44773

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits: 0; none known

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

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-10-02)

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

securitylab.github.com https://securitylab.github.com/advisories/GHSL-2023-092_Notepad__/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

notepad-plus-plus notepad-plus-plus

Classification

Weakness

CWE-120 Buffer Copy without Checking Size of Input
CWE-122 Heap-based Buffer Overflow

References

securitylab.github.com /advisories/GHSL-2023-092_Notepad__/
exploit, third-party-advisory

Sources

CVE List CVE-2023-40166
NVD CVE-2023-40166

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary