CVE-2026-86056Hinoki check available

Local application crash via null session pointer

Published Sep 22, 2026 · Updated Sep 22, 2026

Null pointer dereference in Notepad++ before 8.9.8 allows local users to crash the editor through a crafted NPPM_SAVESESSION message. The handler casts lParam to sessionInfo and dereferences nbFile, files, and sessionFilePathName without first rejecting a null pointer. A process at the same or higher Windows integrity level on the same desktop can terminate the application, causing loss of unsaved documents.

CVSS severityUnavailable
Unscored
EPSS probability0.16%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Null pointer dereference in Notepad++ before 8.9.8 allows local users to crash the editor through a crafted NPPM_SAVESESSION message. The handler casts lParam to sessionInfo and dereferences nbFile, files, and sessionFilePathName without first rejecting a null pointer. A process at the same or higher Windows integrity level on the same desktop can terminate the application, causing loss of unsaved documents.

The record

CVE
CVE-2026-86056
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
Notepad++
Product
Notepad++
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 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=< 8.9.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Notepad++ · Notepad++version=< 8.9.8

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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