CVE-2026-6539

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.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-04-30 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 11:00 UTC Last updatedMost recent change to the record

Details

Published

2026-04-30 21:16 UTC

Last modified

2026-06-17 11:00 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-134

Record status

Analyzed

Affected

• notepad-plus-plus notepad\+\+ 8.9.3

Attack profile CVSS 4.0 · 4.6

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

Active

Confidentiality

Low

Integrity

None

Availability

Low