HCSEC-2026-37 - Consul vulnerable to an authorization bypass in the Connect service mesh

{
  "id": "50ef47220a3042c43d97b7d60fe1dbbb2f03833a7abd412707b55dbce5636c70",
  "url": "https://discuss.hashicorp.com/t/hcsec-2026-37-consul-vulnerable-to-an-authorization-bypass-in-the-connect-service-mesh/77739",
  "method": "llm",
  "payload": {
    "kind": "patch",
    "title": "HCSEC-2026-37 - Consul vulnerable to an authorization bypass in the Connect service mesh",
    "summary": "Consul and Consul Enterprise could generate overly broad Envoy RBAC rules, potentially allowing unauthorized access to a destination service. The issue requires Connect service mesh to be enabled with active intentions; deployments without catalog names containing the affected characters are not impacted in practice.",
    "evidence": "Consul and Consul Enterprise are vulnerable to an authorization bypass in the Connect service mesh that may allow a service to reach a destination it is not authorized to access.",
    "products": [
      {
        "name": {
          "value": "Consul",
          "evidence": "Consul 2.0.4"
        },
        "prerequisites": [
          {
            "value": "Connect service mesh to be enabled with active intentions",
            "evidence": "This issue requires Connect service mesh to be enabled with active intentions."
          }
        ],
        "fixed_versions": [
          {
            "value": "2.0.4",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          }
        ],
        "affected_versions": [
          {
            "value": "1.9.0 through 2.0.3",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          }
        ]
      },
      {
        "name": {
          "value": "Consul Enterprise",
          "evidence": "Consul Enterprise 1.21.18"
        },
        "prerequisites": [
          {
            "value": "Connect service mesh to be enabled with active intentions",
            "evidence": "This issue requires Connect service mesh to be enabled with active intentions."
          }
        ],
        "fixed_versions": [
          {
            "value": "1.21.18",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          },
          {
            "value": "1.22.12",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          },
          {
            "value": "2.0.4",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          }
        ],
        "affected_versions": [
          {
            "value": "1.9.0 through 2.0.3",
            "evidence": "Consul and Consul Enterprise 1.9.0 through 2.0.3; fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12, and 2.0.4."
          }
        ]
      }
    ],
    "severity": "unknown",
    "fixed_cves": [
      {
        "cve": "CVE-2026-88021",
        "product": "Consul",
        "evidence": "This vulnerability (CVE-2026-88021) is fixed in Consul 2.0.4"
      },
      {
        "cve": "CVE-2026-88021",
        "product": "Consul Enterprise",
        "evidence": "This vulnerability (CVE-2026-88021) is fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12 and 2.0.4."
      }
    ],
    "related_cves": [
      {
        "value": "CVE-2026-88021",
        "evidence": "This vulnerability (CVE-2026-88021) is fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12 and 2.0.4."
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "official-hashicorp-discuss-security",
  "document_id": 24003,
  "published_at": "2026-09-10T18:49:49+00:00"
}