CVE-2026-5525

Stack-Based Buffer Overflow in Notepad++ File Drop Handler leads to DoS

HIGH
7.8
CVSS Score
Published: April 10, 2026 at 07:40 AM UTC
Updated: June 17, 2026 at 10:59 AM UTC
1 product affected across 1 vendorNotepad++

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 8.9.4 (unaffected)

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-121

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