CVE-2026-86054
Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path
- State
- Published
- Severity
- 7.8 High
- Published
- Sep 22, 2026
- Updated
- Sep 28, 2026
- Reserved
- Sep 4, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.8 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | GitHub_M |
Weaknesses
- CWE-121 Stack-based Buffer Overflow
Affected Products
| Product | Versions |
|---|---|
notepad-plus-plusnotepad-plus-plus |
|
References
- https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx
- https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf
- https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8
- https://notepad-plus-plus.org/news/v898-released
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