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Digital Employee ExperienceApplication · Teamviewer

CVE-2026-23567

MEDIUM · 6.5 CVSS v3.1 Published 2026-01-29
Fix available
A fix is available. Upgrade to 26.1 or later.
See remediation →
70/100
Remediation priority · Elevated
No privileges 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
An integer underflow in the UDP command handler of the TeamViewer DEX Client (former 1E Client) - Content Distribution Service (NomadBranch.exe) prior version 26.1 for Windows allows an adjacent network attacker to trigger a heap-based buffer overflow and cause a denial-of-service (service crash) via specially crafted UDP packets.

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

An integer underflow vulnerability in the UDP command handler of the TeamViewer DEX Client Content Distribution Service (NomadBranch.exe) allows an adjacent network attacker to send specially crafted UDP packets that trigger a heap-based buffer overflow, causing the service to crash and result in denial-of-service.

MitigationUpgrade NomadBranch.exe to version 26.1 or later. As additional network-level mitigation, restrict UDP access to the service from untrusted network segments.

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
Digital Employee ExperienceApplication
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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Verify TeamViewer DEX NomadBranch.exe is installed
    Locate NomadBranch.exe on the system. Common paths: C:\Program Files\TeamViewer\Remote Device Management\NomadBranch.exe or search via PowerShell: Get-ChildItem -Path 'C:\Program Files' -Recurse -Filter 'NomadBranch.exe' -ErrorAction SilentlyContinue
    Affected if NomadBranch.exe is not found on the system, the service is not installed and this CVE does not apply
  2. Check installed version of NomadBranch.exe
    Right-click NomadBranch.exe, select Properties, then Details tab to view File Version. Alternatively, use PowerShell: (Get-Item 'C:\Program Files\TeamViewer\Remote Device Management\NomadBranch.exe').VersionInfo.FileVersion
    Affected if The version number is less than 26.1 (for example, 25.x, 24.x, etc.)
  3. Confirm UDP service is listening
    Run 'netstat -an | findstr UDP' to list UDP endpoints, or use PowerShell: Get-NetUDPEndpoint | Where-Object {$_.OwningProcess -match 'NomadBranch'}. Also check Windows Services for 'TeamViewer DEX Content Distribution' service status.
    Affected if The NomadBranch UDP listener is active and bound to a port accessible from the network
  4. Assess network exposure of the UDP service
    Check firewall rules: Run 'netsh advfirewall firewall show rule name=all | findstr /i NomadBranch' and review inbound UDP rules. Examine network topology to determine if untrusted adjacent network segments can reach the UDP port.
    Affected if The UDP port is reachable from untrusted/adjacent network segments without proper network segmentation

User is affected if NomadBranch.exe version is below 26.1 AND the UDP handler is exposed to adjacent network attackers who can send specially crafted UDP packets.

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 NomadBranch.exe to version 26.1 or later. As additional network-level mitigation, restrict UDP access to the service from untrusted network segments.

Recommended fix High confidence

TeamViewer DEX Client version 26.1

  1. Identify all systems running TeamViewer DEX Client (formerly 1E Client) - Content Distribution Service (NomadBranch.exe) on Windows
  2. Check the current version of the NomadBranch.exe service on each affected system
  3. Upgrade the TeamViewer DEX Client to version 26.1 or later
  4. Verify the upgraded version by checking that NomadBranch.exe is now at version 26.1 or higher
  5. Restart the Content Distribution Service if not automatically restarted after upgrade

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

Fix this in Digital Employee Experience Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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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-2026-23567 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data