CVE-2026-5525: Notepad-Plus-Plus Notepad++

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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).

Affected products

• Notepad-Plus-Plus Notepad++: version 8.9.3 only

Published 2026-04-10. Last modified 2026-06-17.