TeamSpeak 3 Server up to 3.13.7 ECC Key Parser heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.7$0-$5k0.95

Summaryinfo

A vulnerability was found in TeamSpeak 3 Server up to 3.13.7. It has been classified as critical. This issue affects some unknown processing of the component ECC Key Parser. Performing a manipulation results in heap-based overflow. This vulnerability is known as CVE-2026-4391. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in TeamSpeak 3 Server up to 3.13.7. It has been classified as critical. This affects an unknown code block of the component ECC Key Parser. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on availability.

The weakness was published by Michael Imfeld with modzero as MZ-26-01. It is possible to read the advisory at modzero.com. This vulnerability is uniquely identified as CVE-2026-4391. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly 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-2026-32585). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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

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

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
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-2026-4391 (🔒)
GCVE (CVE): GCVE-0-2026-4391
GCVE (VulDB): GCVE-100-366315
EUVD: 🔒

Entryinfo

Created: 05/27/2026 18:22
Updated: 05/27/2026 21:12
Changes: 05/27/2026 18:22 (53), 05/27/2026 18:26 (23), 05/27/2026 21:12 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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