CVE-2026-77605Public exploit

Command execution via sibling script path confusion

Published Sep 22, 2026 · Updated Sep 22, 2026

Improper path resolution in Notepad++ before 8.9.8 allows attackers to execute a sibling command script through Run by system. The Folder as Workspace action passes the selected text-file path to cmd.exe, which resolves and executes a same-named .cmd sibling instead of the literal file. An attacker must place the sibling script and persuade a user on Windows 10 or Windows 11 to invoke Run by system; commands run with the user's privileges.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper path resolution in Notepad++ before 8.9.8 allows attackers to execute a sibling command script through Run by system. The Folder as Workspace action passes the selected text-file path to cmd.exe, which resolves and executes a same-named .cmd sibling instead of the literal file. An attacker must place the sibling script and persuade a user on Windows 10 or Windows 11 to invoke Run by system; commands run with the user's privileges.

The record

CVE
CVE-2026-77605
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
Notepad++
Product
Notepad++
Classifications
CWE-20, CWE-706, T1059.003, T1204.002
Attack vector
local
Privileges
unauthenticated

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 privilegesunauthenticated

What is affected?

Notepad++ · Notepad++version=< 8.9.8

Published CVSS scores

7.8GitHub Security AdvisoryCVSS: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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-706Use of Incorrectly-Resolved Name or Reference
T1059.003Windows Command Shell
T1204.002Malicious File

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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