CVE-2026-5525Public exploit

Application crash via file-drop path overflow

Published Apr 10, 2026 · Updated Apr 10, 2026

Stack-based buffer overflow in Notepad++ 8.9.3 allows local users to crash the application via a crafted dropped directory path. Notepad_plus::dropFiles appends a backslash and null terminator to a full 260-wide-character stack buffer without reserving two slots. Exploitation requires a user to drag a 259-character Windows directory path without a trailing backslash; the observed consequence is process termination.

CVSS severity6.0
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Notepad++ 8.9.3 allows local users to crash the application via a crafted dropped directory path. Notepad_plus::dropFiles appends a backslash and null terminator to a full 260-wide-character stack buffer without reserving two slots. Exploitation requires a user to drag a 259-character Windows directory path without a trailing backslash; the observed consequence is process termination.

The record

CVE
CVE-2026-5525
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
Notepad++
Product
Notepad++
Classifications
CWE-121, T1204
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.9.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Notepad++ · Notepad++version=8.9.3

Published CVSS scores

6.0securinCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1204User Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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