Denial-of-Service Vulnerability in SoftEther VPN Developer Edition
CVE-2026-39312

7.5HIGH

Key Information:

Vendor

Softethervpn

Status
Softethervpn
Vendor
CVE Published:
7 April 2026

What is CVE-2026-39312?

SoftEther VPN Developer Edition versions up to 5.2.5188 are susceptible to a denial-of-service vulnerability that enables unauthenticated attackers to crash the vpnserver process. This can be achieved by sending a single, malformed EAP-TLS packet over raw L2TP (UDP/1701), effectively terminating all active VPN sessions. The flaw presents significant risks for users relying on this VPN solution for secure communication.

Affected Version(s)

SoftEtherVPN <= 5.2.5188

References

https://github.com/SoftEtherVPN/SoftEtherVPN/security/adv...
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CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.