PSIRT ZTNA Portal Improper Certificate Validation

{
  "id": "c73ad7d2687eb17d7cfcae716370cc687c3d964b5da97609bd1c618b61618efb",
  "url": "https://fortiguard.fortinet.com/psirt/FG-IR-26-174",
  "method": "llm",
  "payload": {
    "kind": "patch",
    "title": "PSIRT ZTNA Portal Improper Certificate Validation",
    "summary": "An improper certificate validation vulnerability in the FortiOS and FortiProxy Agentless ZTNA portal may enable an unauthenticated remote attacker to perform a man-in-the-middle attack. Upgrade affected FortiOS and FortiProxy versions to 7.6.7 or above.",
    "evidence": "An improper certificate validation vulnerability [CWE-295] in FortiOS and FortiProxy Agentless ZTNA portal may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the ZTNA portal and the backend destination website.",
    "products": [
      {
        "name": {
          "value": "FortiOS",
          "evidence": "FortiOS 7.6"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.6.7 or above",
            "evidence": "FortiOS 7.6 7.6.1 through 7.6.6 Upgrade to 7.6.7 or above"
          }
        ],
        "affected_versions": [
          {
            "value": "7.6.1 through 7.6.6",
            "evidence": "FortiOS 7.6 7.6.1 through 7.6.6 Upgrade to 7.6.7 or above"
          }
        ]
      },
      {
        "name": {
          "value": "FortiProxy",
          "evidence": "FortiProxy 7.6"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.6.7 or above",
            "evidence": "FortiProxy 7.6 7.6.2 through 7.6.6 Upgrade to 7.6.7 or above"
          }
        ],
        "affected_versions": [
          {
            "value": "7.6.2 through 7.6.6",
            "evidence": "FortiProxy 7.6 7.6.2 through 7.6.6 Upgrade to 7.6.7 or above"
          }
        ]
      }
    ],
    "severity": "high",
    "fixed_cves": [],
    "related_cves": [
      {
        "value": "CVE-2026-84393",
        "evidence": "CVE ID CVE-2026-84393"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "Severity High"
  },
  "source_id": "official-fortinet-psirt",
  "document_id": 23571,
  "published_at": "2026-09-08T07:00:00+00:00"
}