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CVE-2026-39312

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

Published: Apr 7, 2026Updated: Apr 14, 2026 Sources: CVE List NVDCWE-789
NVD MITRE
7.5CVSSHIGH
EPSS Score
0.4%
Top 64.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-789

Affected Products

SoftEtherVPNSoftEtherVPN
On-prem
Networking Infrastructure / vpn-gateway
softethervpnsoftether
On-prem
Networking Infrastructure / vpn-gateway
softethervpnoss-projectNetworking Infrastructure
softetheross-projectNetworking Infrastructureaka softether vpn, softether vpn server

Exploitability

Workaround Available

References

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

Timeline

Published
Apr 7, 2026
Last Updated
Apr 14, 2026

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