Medium 4.4Published Apr 30, 2026

CVE-2026-6539Notepad++ 8.9.3 Format String Injection via nativeLang.xml

Updated under an hour ago (Oct 26, 2026, 2:30 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

Notepad++ 8.9.3 contains a format string injection vulnerability in the Find Results panel handler that allows attackers to cause denial of service and information disclosure by crafting a malicious nativeLang.xml language pack file. Attackers can distribute a poisoned language pack through community channels that triggers format string interpretation when a user performs search operations, leading to access violations and potential leakage of stack or register contents.

CVSS: 4.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Weakness (CWE): CWE-134
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Analyzed
Record last updated: Jul 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Notepad++ Notepad++ notepad++:notepad++ (from the name)	before 8.9.4	CNA record
notepad-plus-plus notepad++ notepad-plus-plus:notepad++	8.9.3	NVD

References

References

https://notepad-plus-plus.org/news/v894-released/	patch, release-notes
https://www.vulncheck.com/advisories/notepad-format-string-injection-via-nativelang-xml	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.