Information Disclosure via DNS Rebinding in IBM ContextForge MCP Gateway

IBM ContextForge MCP Gateway (mcp-contextforge-gateway) versions 1.0.6 and earlier are vulnerable to a DNS rebinding flaw during the tool invocation process. This vulnerability allows an attacker who has already achieved authenticated access to the gateway to manipulate DNS resolution to circumvent security controls. By performing a DNS rebinding attack, the adversary can force the gateway to interact with unintended internal resources or services, ultimately leading to the unauthorized disclosure of sensitive data processed by the MCP (Model Context Protocol) gateway. Defenders should prioritize patching, as this vulnerability represents a significant risk to the confidentiality of data handled by the ContextForge integration.

Impact

Successful exploitation of this vulnerability enables a remote authenticated attacker to bypass intended security boundaries within the MCP infrastructure. This can result in the exfiltration of sensitive information processed by the gateway, potentially leading to unauthorized data exposure across internal systems integrated with ContextForge.

Recommendation

• Upgrade to IBM ContextForge MCP Gateway version 1.0.7 or later to remediate CVE-2026-18905.
• Audit logs for authenticated sessions that perform unusually frequent or rapid DNS resolution changes during tool execution.
• Implement strict egress filtering on the gateway host to restrict connections to authorized internal and external endpoints.