Vulnerability 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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Softether | Softethervpn | <= 5.2.5188 |
Related Weaknesses (CWE)
References
- https://github.com/SoftEtherVPN/SoftEtherVPN/security/advisories/GHSA-q5g3-qhc6-ExploitMitigationVendor Advisory
- https://github.com/SoftEtherVPN/SoftEtherVPN/security/advisories/GHSA-q5g3-qhc6-ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-39312?
CVE-2026-39312 is a vulnerability with a CVSS score of 7.5 (HIGH). 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....
How severe is CVE-2026-39312?
CVE-2026-39312 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-39312?
Check the references section above for vendor advisories and patch information. Affected products include: Softether Softethervpn.