TeamSpeak 3 Server up to 3.13.7 clientek Handshake proof assertion

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in TeamSpeak 3 Server up to 3.13.7. It has been declared as critical. Impacted is an unknown function of the component clientek Handshake Handler. Executing a manipulation of the argument proof can lead to assertion. This vulnerability is handled as CVE-2026-4392. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in TeamSpeak 3 Server up to 3.13.7. It has been declared as critical. This vulnerability affects some unknown processing of the component clientek Handshake Handler. The manipulation of the argument proof with an unknown input leads to a assertion vulnerability. The CWE definition for the vulnerability is CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. As an impact it is known to affect availability.

The weakness was released by Michael Imfeld with modzero as MZ-26-01. The advisory is shared for download at modzero.com. This vulnerability was named CVE-2026-4392. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 3.13.8 eliminates this vulnerability. The upgrade is hosted for download at teamspeak.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-32592). Once again VulDB remains the best source for vulnerability data.

Affected

  • TeamSpeak 3 Server up to 3.13.7
  • TeamSpeak SDK Server-Side Integrations up to 3.3.1

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.7

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score: 7.5
Vendor Vector: 🔒

Researcher Base Score: 7.5
Researcher Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Assertion
CWE: CWE-617
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: TeamSpeak 3 Server 3.13.8

Timelineinfo

05/27/2026 Advisory disclosed
05/27/2026 +0 days VulDB entry created
05/27/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: MZ-26-01
Researcher: Michael Imfeld
Organization: modzero
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2026-4392 (🔒)
GCVE (CVE): GCVE-0-2026-4392
GCVE (VulDB): GCVE-100-366316
EUVD: 🔒

Entryinfo

Created: 05/27/2026 18:22
Updated: 05/27/2026 21:12
Changes: 05/27/2026 18:22 (54), 05/27/2026 18:26 (23), 05/27/2026 18:27 (1), 05/27/2026 21:12 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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