ReviewHigh

CVE-2026-57233

notepad-plus-plus

Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the WinGup decompress function joins untrusted ZIP entry names to unzipDestTo without canonical containment validation, allowing an entry such as ../mimeTools/mimeTools.dll to overwrite a DLL in a sibling plugin directory and execute attacker-controlled code when Notepad++ next loads that plugin. This issue is fixed in version 8.9.7.

CVSS: 8.1
EPSS: -
CISA KEV: Not listed
Published: 2026.08.18

PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 8.1

Vulnerability overview

Affected product and versions

Product: notepad-plus-plus
Affected versions: < 8.9.7
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that notepad-plus-plus and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
CWE: CWE-22