How severe is CVE-2026-4391?

CVE-2026-4391 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-4391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-4391?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-4391 have an EU (EUVD) identifier?

Yes. CVE-2026-4391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32585.

When was CVE-2026-4391 published?

CVE-2026-4391 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2026-4391

CVE-2026-4391 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
CVSS v4: 6.9
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32585
Weakness: CWE-119
Published: 2026-05-27
Last modified: 2026-06-17

Description

A security vulnerability has been detected in TeamSpeak 3 Server up to 3.13.7. This vulnerability affects unknown code of the component ECC Key Parser. Such manipulation leads to heap-based buffer overflow. The attack may be launched remotely. Upgrading to version 3.13.8 is able to resolve this issue. It is suggested to upgrade the affected component.

Frequently asked questions

What is CVE-2026-4391?: A security vulnerability has been detected in TeamSpeak 3 Server up to 3.13.7. This vulnerability affects unknown code of the component ECC Key Parser. Such manipulation leads to heap-based buffer overflow. The attack may be launched remotely. Upgrading to version 3.13.8 is able to resolve this issue. It is suggested to upgrade the affected component.
How severe is CVE-2026-4391?: CVE-2026-4391 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-4391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4391?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4391 have an EU (EUVD) identifier?: Yes. CVE-2026-4391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32585.
When was CVE-2026-4391 published?: CVE-2026-4391 was published on 2026-05-27 and last updated on 2026-06-17.

References

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

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CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

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