Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path
Summary
| CVE | CVE-2026-86054 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-22 18:17:23 UTC |
| Updated | 2026-09-23 18:28:25 UTC |
| Description | Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in NppParameters::writeSession in PowerEditor/src/Parameters.cpp because it copies a session path derived from -settingsDir= into backupPathName[MAX_PATH] with unbounded wcscpy and appends SESSION_BACKUP_EXT with unbounded wcscat. A sufficiently long settings directory causes the backup suffix to exceed the fixed stack buffer when Notepad++ saves the session, and the protected release build terminates through its stack canary, causing denial of service. This issue is fixed in version 8.9.8. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.002020000 probability, percentile 0.103670000 (date 2026-09-23)
Problem Types: CWE-121 | CWE-121 CWE-121: Stack-based Buffer Overflow
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Notepad-plus-plus | Notepad-plus-plus | affected < 8.9.8 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| notepad-plus-plus.org/news/v898-released | [email protected] | notepad-plus-plus.org | |
| github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-... | [email protected] | github.com | |
| github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be771588... | [email protected] | github.com | |
| github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.