CVE-2026-23564

Adjacent-network disclosure via cleartext UDP transmission

Published Jan 29, 2026 · Updated Jan 29, 2026

Cleartext transmission in TeamViewer DEX Client before 26.1 allows adjacent-network attackers to disclose sensitive UDP traffic. The Content Distribution Service in NomadBranch.exe sends normally encrypted UDP traffic in cleartext after an attacker-induced condition, but TeamViewer has not disclosed the triggering packet or code path. The Windows service must be enabled, and its default disabled state prevents exposure.

CVSS severity6.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext transmission in TeamViewer DEX Client before 26.1 allows adjacent-network attackers to disclose sensitive UDP traffic. The Content Distribution Service in NomadBranch.exe sends normally encrypted UDP traffic in cleartext after an attacker-induced condition, but TeamViewer has not disclosed the triggering packet or code path. The Windows service must be enabled, and its default disabled state prevents exposure.

The record

CVE
CVE-2026-23564
Published
Jan 29, 2026
Updated
Jan 29, 2026
Vendor
TeamViewer
Product
TeamViewer DEX Client
Classifications
CWE-319, CAPEC-220, T1040
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 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=0 <26.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

TeamViewer · TeamViewer DEX Clientversion=0 <26.1

Published CVSS scores

6.5TeamViewer Germany GmbHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
CAPEC-220Client-Server Protocol Manipulation
T1040Network Sniffing

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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