dbcve.org
MobaxtermApplication · Mobatek

CVE-2026-25866

HIGH · 7.8 CVSS v3.1 Published 2026-03-09
Fix available
A fix is available. Upgrade to 26.1 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
MobaXterm versions prior to 26.1 contain an uncontrolled search path element vulnerability. The application calls WinExec to execute Notepad++ without a fully qualified executable path when opening remote files. An attacker can exploit the search path behavior by placing a malicious executable earlier in the search order, resulting in arbitrary code execution in the context of the affected user.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

MobaXterm versions prior to 26.1 use WinExec to launch Notepad++ for viewing remote files without specifying a fully qualified path. This allows Windows' executable search order to be hijacked if an attacker places a malicious notepad++.exe in a directory that appears earlier in the system PATH, resulting in arbitrary code execution under the user's context.

MitigationUpgrade to MobaXterm version 26.1 or later, which implements fully qualified paths when invoking external executables. As a temporary workaround, ensure the directory containing legitimate Notepad++ appears earliest in the PATH before any attacker-writable locations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MobaxtermApplication
Affected:< 26.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check MobaXterm installed version
    Open MobaXterm and go to Help > About, or check the executable properties of the MobaXterm installation directory for the version number
    Affected if The installed version is earlier than 26.1 (e.g., 26.0, 25.x, etc.)
  2. Verify Notepad++ is configured as the default viewer
    In MobaXterm settings, check under Settings > General > File handling for the text file viewer configuration, or attempt to open a remote text file and observe which editor launches
    Affected if Notepad++ is set as the default text file viewer and will be invoked via WinExec
  3. Inspect system PATH for attacker-writable directories
    Open Command Prompt and run 'echo %PATH%' to view the PATH environment variable, or use 'set PATH' to see the full system and user PATH values
    Affected if Any directory listed in PATH before the legitimate Notepad++ location (commonly C:\Program Files\Notepad++ or C:\Program Files (x86)\Notepad++) is writable by an untrusted user or accessible to an attacker
  4. Check for presence of notepad++.exe in unexpected PATH locations
    Run 'where notepad++' from Command Prompt to list all notepad++..exe locations found in PATH order, or manually search for notepad++.exe in directories that appear before the official Notepad++ installation folder
    Affected if Multiple notepad++.exe files exist in PATH and the first one found is not in the official Notepad++ installation directory

You are affected if MobaXterm version is below 26.1, Notepad++ is configured as the remote file viewer, and any directory preceding the legitimate Notepad++ location in your PATH is writable by an attacker.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 26.1 or later
Fixed in 26.1
Interim mitigation

Upgrade to MobaXterm version 26.1 or later, which implements fully qualified paths when invoking external executables. As a temporary workaround, ensure the directory containing legitimate Notepad++ appears earliest in the PATH before any attacker-writable locations.

Recommended fix High confidence

26.1

  1. Navigate to the official MobaXterm download page at mobaxterm.mobatek.net
  2. Download MobaXterm version 26.1 or later
  3. Run the installer and follow the prompts to upgrade your existing installation
  4. Launch MobaXterm and verify the version number shows 26.1 or higher

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mobaxterm Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-25866 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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