CVE-2026-6539CWE-134

Notepad++ 8.9.3 Format String Injection via nativeLang.xml

Medium · published April 30, 2026

CVSS v4.0
4.6
EPSS
0%
Percentile
8.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
4.6 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00194 · 8.6th percentile
Weakness
CWE-134 · Use of Externally-Controlled Format String
Published
2026-04-30T20:31Z
EPSS history
Timeline
  • 30 APR 20:31Z
    Notepad++ 8.9.3 Format String Injection via nativeLang.xml
    cvelistv5