CVE-2026-23564VulnerabilityPublished 29 Jan 2026

CVE-2026-23564: TeamViewer DEX · Cleartext Transmission

Affects TeamViewer DEXSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium : upgrade to 26.1 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 26.1

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

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade TeamViewer DEX to 26.1.

Affected software

Product	Affected	Fixed in
TeamViewerDEX	Affected <26.1	Fixed in 26.1

AI-suggested

European organizations should prioritize upgrading TeamViewer DEX Client to version 26.1 or later as soon as it becomes available to ensure the vulnerability is patched. If you cannot patch yet, network administrators should enforce strict network segmentation and access controls to limit the ability of unauthorized devices to connect to the same local network segments as TeamViewer DEX clients. Deploying network monitoring tools to detect unusual UDP traffic patterns may help identify potential exploitation attempts. Additionally, organizations should consider encrypting sensitive data at the application layer before transmission to mitigate risks from cleartext exposure. Regularly auditing and updating endpoint security policies to restrict installation and use of vulnerable software versions is recommended. Finally, educating IT staff about the risks of adjacent network attacks and enforcing strong network access controls can further reduce exposure.

Description

A vulnerability in TeamViewer DEX Client (former 1E Client) - Content Distribution Service (NomadBranch.exe) prior version 26.1 for Windows allows an attacker on the adjacent network to cause normally encrypted UDP traffic to be sent in cleartext. This can result in disclosure of sensitive information.

Impact

For European organizations, this vulnerability could lead to unauthorized disclosure of sensitive information transmitted via TeamViewer DEX's content distribution service. Organizations that rely on TeamViewer DEX for internal content distribution over local networks are particularly vulnerable, as attackers on the same network can intercept unencrypted UDP traffic. This exposure could compromise confidential business data, intellectual property, or personal data, potentially violating GDPR requirements. The lack of impact on integrity and availability limits the threat to data confidentiality, but the sensitivity of the leaked information could still result in reputational damage, regulatory penalties, and operational risks. Industries with high data sensitivity such as finance, healthcare, and government entities in Europe are at elevated risk. Since exploitation requires network adjacency, organizations with segmented and well-controlled internal networks may reduce exposure, but those with flat or poorly segmented networks face higher risks. The absence of known exploits in the wild reduces immediate urgency but does not eliminate the risk of future exploitation.

CWE-319Cleartext Transmission of Sensitive Information (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.
Architecture and Design
Before transmitting, encrypt the data using reliable, confidentiality-protecting cryptographic protocols.
Implementation
When using web applications with SSL, use SSL for the entire session from login to logout, not just for the initial login page.
Implementation
When designing hardware platforms, ensure that approved encryption algorithms (such as those recommended by NIST) protect paths from security critical data to trusted user applications.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.1 (opens in a new tab)
V9.2.2 (opens in a new tab)
V1.9.1 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Harvesting Information via API Event Monitoring (opens in a new tab)
Signature Spoofing by Mixing Signed and Unsigned Content (opens in a new tab)
Sniff Application Code (opens in a new tab)
Interception (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

teamviewer.com/en/resources/trust-center/security-bulletins/tv-2026-1001/ (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Jan 2026, 09:29 UTC

WeaknessesCWE-319

Technical details

References

Community reviews

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