Stack-Based Buffer Overflow in Notepad++ File Drop Handler leads to DoS
Priority HIGH 69CWE-121Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.
Summary
A stack-based buffer overflow vulnerability exists in Notepad++ version 8.9.3 in the file drop handler component. When a user drags and drops a directory path of exactly 259 characters without a trailing backslash, the application appends a backslash and null terminator without proper bounds checking, resulting in a stack buffer overflow and application crash (STATUS_STACK_BUFFER_OVERRUN).
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00168 6th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Notepad++ (Notepad++ Project): 8.9.4
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Notepad++ Project | Notepad++ | 8.9.3 | 8.9.4 | Patch available | CNA |
- Notepad++ VendorNotepad++ Project Affected 8.9.3 Fixed in 8.9.4 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:notepad-plus-plus:notepad\+\+:8.9.3:*:*:*:*:*:*:* | 8.9.3 | Vulnerable | notepad-plus-plus |
- cpe:2.3:a:notepad-plus-plus:notepad\+\+:8.9.3:*:*:*:*:*:*:* Versions 8.9.3 Vulnerable ·notepad-plus-plus
Remediation
- Fix · CNA Notepad++ (Notepad++ Project) Fixed in 8.9.4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-5525
- 2026-10-03 Alias added: GHSA-8hrp-2fqv-gvrx
References
More Notepad++ Project vulnerabilities
- TI-2023-00861 cxasm notepad-- Directory Comparison denial of service CVSS 3.1MEDIUM 5.5
Sources
- CVE-2026-5525 · CVE Program
- CVE-2026-5525 · NVD
- FIRST EPSS
- GHSA-8hrp-2fqv-gvrx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences