CVE-2026-39312

Summary

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.

Affected Software

VendorProductVersion RangeStatus
SoftEtherVPNSoftEtherVPN<= 5.2.5188affected

Weaknesses

  • CWE-789: CWE-789: Memory Allocation with Excessive Size Value

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References