CVE-2026-4391 TeamSpeak CVE debrief

Who should care

Organizations operating TeamSpeak 3 Server infrastructure for voice communications, gaming communities, enterprise collaboration, or customer support channels. System administrators responsible for voice server maintenance and security patching. Security teams monitoring for remote code execution or denial of service vulnerabilities in communication platforms.

Technical summary

The vulnerability exists in the ECC (Elliptic Curve Cryptography) Key Parser component of TeamSpeak 3 Server. A heap-based buffer overflow occurs when parsing malformed ECC key data, allowing an attacker to corrupt heap memory. The attack vector is network-based with low complexity and requires no authentication or user interaction. The CVSS 4.0 score of 6.9 (Medium) reflects primarily availability impact. The vulnerability is classified under CWE-119 and CWE-122, indicating improper bounds checking during memory operations. Successful exploitation could lead to denial of service conditions or potentially other unspecified impacts depending on memory layout and server configuration.

Defensive priority

medium

Recommended defensive actions

• Upgrade TeamSpeak 3 Server to version 3.13.8 or later to remediate the heap-based buffer overflow vulnerability in the ECC Key Parser component
• Verify current TeamSpeak 3 Server version and confirm it is not running 3.13.7 or earlier
• Review server logs for anomalous connection attempts or crashes that may indicate exploitation attempts against the ECC Key Parser
• If immediate patching is not feasible, consider restricting network access to the TeamSpeak 3 Server to trusted sources until the upgrade can be completed
• Monitor vendor security advisories for additional guidance or updated remediation information

Evidence notes

The vulnerability was disclosed on 2026-05-27 with NVD status 'Deferred'. The CVSS 4.0 vector indicates network attack vector with low attack complexity, no privileges required, and low availability impact. CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-122 (Heap-based Buffer Overflow) are identified as the underlying weaknesses. Multiple independent sources corroborate the vulnerability details including the vendor security advisory and third-party security research.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.