PatchTheCVECVE-2026-86056: Notepad++ is a free and open-source source code editor
CVE-2026-86056 is a medium-severity flaw (CVSS 5.5) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.5 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 95%) |
| CISA exploited list | No |
| Weakness | CWE-476 |
| Published | 2026-09-22 |
| Last modified | 2026-09-23 |
Last updated 2026-09-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-86056?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-86056 being exploited?
CVE-2026-86056 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-86056 affect?
CVE-2026-86056 affects affected software. Severity is medium (CVSS 5.5). 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 me
How urgent is CVE-2026-86056?
Priority 21/100. No elevated risk signals yet.
Software pages
Windows vulnerabilities · Notepad++ vulnerabilities