CVE-2026-39312

HIGH

Pre-Auth EAP-TLS DoS on SoftEther VPN Developer Edition

Title source: cna

Description

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.

References (1)

[X_Refsource_Confirm] https://github.com/SoftEtherVPN/SoftEtherVPN/security/advisories/GHSA-q5g3-qhc6-pr3h

Scores

CVSS v3 7.5

EPSS 0.0025

EPSS Percentile 48.2%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation poc

Automatable yes

Technical Impact partial

Details

CWE

CWE-789

Status published

Products (2)

softether/softethervpn < 5.2.5188

SoftEtherVPN/SoftEtherVPN <= 5.2.5188

Published Apr 07, 2026

Tracked Since Apr 07, 2026