CVE-2026-39312 HIGH

CVE-2026-39312: Pre-Auth EAP-TLS DoS on SoftEther VPN Developer Edition

Vendor Softethervpn
Product SoftEtherVPN
Weakness CWE-789
Published April 7, 2026
Last update April 7, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

SoftEtherVPN is a an open-source cross-platform multi-protocol VPN Program. In 5.2.5188 and earlier, a pre-authentication denial-of-service vulnerability exists in SoftEther VPN Developer Edition 5.2.5188 (and likely earlier versions of Developer Edition). An unauthenticated remote attacker can crash the vpnserver process by sending a single malformed EAP-TLS packet over raw L2TP (UDP/1701), terminating all active VPN sessions.

Key dates

02Disclosure timeline

April 7, 2026 CVE published
April 7, 2026 Record updated