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

{
  "id": "653c5e4eb9dec62de7cdc5f549ccc052d8bbfb32d719ca2ba29ac98284869353",
  "url": "https://osv.dev/vulnerability/CVE-2026-39312",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Pre-Auth EAP-TLS DoS on SoftEther VPN Developer Edition",
    "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.",
    "evidence": "osv:CVE-2026-39312",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-39312",
      "aliases": [
        "CVE-2026-39312",
        "GHSA-q5g3-qhc6-pr3h"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/softethervpn/softethervpn",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "10d6efcc5e3329e5a959a99c6e939648f41121bf"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "5.2.5188"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:softether:softethervpn:*:*:*:*:developer:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "5.2.5188"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "5.2.5188",
            "5.02.5187",
            "5.02.5186",
            "5.02.5185",
            "5.02.5184",
            "5.02.5183",
            "5.02.5182",
            "5.02.5181",
            "5.02.5180",
            "5.02.0",
            "5.01.9674",
            "5.01.9673",
            "5.01.9672",
            "5.01.9671",
            "5.01.9670",
            "5.01.9669",
            "5.01.9668",
            "5.01.9667",
            "5.01.9666",
            "5.01.9665",
            "5.01.9664",
            "5.01.9663",
            "5.01.9662",
            "5.01.9661",
            "5.01.9660",
            "5.01.9659",
            "5.01.9658"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39312.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.176141792Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39312.json",
        "https://github.com/SoftEtherVPN/SoftEtherVPN/security/advisories/GHSA-q5g3-qhc6-pr3h",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-39312"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-789"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39312.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-39312",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491952,
  "published_at": "2026-04-07T16:52:08.172+00:00"
}