Cross-tenant credential reuse in HashiCorp Terraform MCP Server (CVE-2026-16498)

The terraform-mcp-server before version 1.1.0 contains a cross-tenant credential reuse vulnerability in stateless streamable-HTTP transport mode. Because the server's per-session Terraform client cache relies on session identifiers to distinguish between users, and the underlying MCP library does not assign unique session identifiers to requests in stateless mode, credentials supplied by one tenant may be reused for subsequent requests from other tenants regardless of the credentials those tenants supplied. This could allow one user's Terraform token to be used to execute tool calls on behalf of subsequent users. Affected versions: - terraform-mcp-server 0.2.1 up to and including 1.0.0 We recommend updating to: 1.1.0. CVSS 10.0 · our assessment: act_now Reference: https://discuss.hashicorp.com/t/hcsec-2026-23-multiple-vulnerabilities-impacting-hashicorp-terraform-mcp-server/77606 Details: https://vuln.today/cve/CVE-2026-16498