terraform-mcp-server vulnerable to cross-user credential inheritance if an MCP session ID is obtained by another user

{
  "id": "d08aea7471cbddca0c02453e387f1c131458fe5dff3726165e08fafcc8152bbe",
  "url": "https://osv.dev/vulnerability/CVE-2026-16496",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "terraform-mcp-server vulnerable to cross-user credential inheritance if an MCP session ID is obtained by another user",
    "summary": "The terraform-mcp-server before version 1.1.0 is vulnerable to an authorization bypass in the streamable-HTTP stateful transport mode that may allow a user who obtains another user's MCP session ID to have their tool calls executed using that user's Terraform credentials. This vulnerability, CVE-2026-16496, is fixed in terraform-mcp-server 1.1.0.",
    "evidence": "osv:CVE-2026-16496",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-16496",
      "aliases": [
        "BIT-consul-2026-16496",
        "CVE-2026-16496"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/hashicorp/terraform-mcp-server",
              "type": "GIT",
              "events": [
                {
                  "introduced": "22ae2e9368890031a68816c9fb1db91afaeb078c"
                },
                {
                  "fixed": "0a0dee37613f40a58c1a16392ee90baa117fdfcd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.3.0"
                      },
                      {
                        "fixed": "1.1.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-16496.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.439855147Z",
      "provider": "osv",
      "references": [
        "https://discuss.hashicorp.com/t/hcsec-2026-23-multiple-vulnerabilities-impacting-hashicorp-terraform-mcp-server/77606",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16496.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-16496",
        "https://github.com/hashicorp/terraform-mcp-server"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-384"
        ],
        "cna_assigner": "HashiCorp",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16496.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-16496",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504904,
  "published_at": "2026-07-28T17:57:36.795+00:00"
}