CVE-2026-4391TeamSpeak 3 Server ECC Key heap-based overflow
- 6.9MediumCVSS base score
- 0.65%Exploitation in 30 daysEPSS · top 48% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
A security vulnerability has been detected in TeamSpeak 3 Server up to 3.13.8. 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 3.13.9 is able to resolve this issue. It is suggested to upgrade the affected component. The vendor explains: "We have just released TeamSpeak 3 Server 3.13.9 to address a remaining variant of CVE-2026-4391, affecting ECC key parsing during the connection handshake. The original fix released with 3.13.8 did not cover this additional variant, which could allow an unauthenticated remote attacker to crash the server using specially crafted input."
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By VulDB
- 2 months later
· 2 months later
Published
- 6 months later
· 6 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X |
| VulDBCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C |
| VulDBCNA (assigner) | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C |
| VulDBCNA (assigner) | 2.0 | Medium5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P/E:ND/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.65% · top 48% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Affected products
TeamSpeak 3 Server
- affected 3.13.0
- affected 3.13.1
- affected 3.13.2
- affected 3.13.3
- affected 3.13.4
- affected 3.13.5
- affected 3.13.6
- affected 3.13.7
- affected 3.13.8
- unaffected 3.13.9
References
References7
- VDB-366315 | TeamSpeak 3 Server ECC Key heap-based overflow (opens in a new tab)vdb-entry
- VDB-366315 | CTI Indicators (IOB, IOC) (opens in a new tab)signaturepermissions-required
- CVE-2026-4391 | CVE Analysis and Report (opens in a new tab)third-party-advisory
- https://modzero.com/en/advisories/mz-26-01-teamspeak/ (opens in a new tab)related
- https://files.teamspeak-services.com/docs/security/TS-SA-2026-001.html (opens in a new tab)related
- https://www.teamspeak.com/en/downloads/#server (opens in a new tab)patch
- https://community.teamspeak.com/t/teamspeak-3-server-3-13-9-security-update/65759 (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-32585 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-4391)Record last updated .