NULL pointer dereference in Notepad-Plus-Plus
CVE-2026-86056
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, the NPPM_SAVESESSION handler in PowerEditor/src/NppBigSwitch.cpp converts lParam to a sessionInfo pointer and dereferences its nbFile, files, and sessionFilePathName members without checking for null. A process running at the same or a higher Windows integrity level on the same desktop can send NPPM_SAVESESSION with a null lParam, immediately terminating Notepad++ and causing denial of service and loss of unsaved documents. This issue is fixed in version 8.9.8.
Published .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Notepad-Plus-Plus — versions < 8.9.8
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-86056?
- CVE-2026-86056 is a medium-severity vulnerability in Notepad-Plus-Plus, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-09-22.
- How severe is CVE-2026-86056?
- Medium severity. CVSS v3 base score is 5.5 out of 10.