CVE-2026-18905

Analyzed Analyzed - Analysis Complete

DNS Rebinding in IBM ContextForge MCP Gateway

Publication date: 2026-09-04

Last updated on: 2026-09-15

Assigner: IBM Corporation

Description

IBM ContextForge MCP Gateway (`mcp-contextforge-gateway`) <= v1.0.6 MCP Context Forge could allow a remote authenticated attacker to obtain sensitive information due to a DNS rebinding vulnerability during tool invocation.

CVSS Scores

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Meta Information

Published

2026-09-04

Last Modified

2026-09-15

Generated

2026-09-25

AI Q&A

2026-09-04

EPSS Evaluated

2026-09-23

NVD

CVE-2026-18905

EUVD

EUVD-2026-71315

Affected Vendors & Products

Vendor	Product	Version / Range
ibm	contextforge	to 1.0.6 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

Executive Summary

IBM ContextForge MCP Gateway versions up to v1.0.6 have a DNS rebinding vulnerability during tool invocation. The gateway validates REST tool target URLs only once at registration and does not re-validate DNS resolution when the tool is used. This allows a remote authenticated attacker to redirect outbound requests to internal network targets by changing DNS records after registration.

Detection Guidance

To detect this vulnerability, monitor DNS resolution changes for registered tool URLs and inspect outbound requests from the IBM ContextForge MCP Gateway. Check for unauthorized internal network access attempts or unexpected external connections. Review logs for tool invocation requests to domains with recent DNS changes.

Impact Analysis

This vulnerability could allow a remote authenticated attacker to access sensitive information by redirecting gateway requests to internal systems. The attacker needs low privileges but can exploit the DNS rebinding to bypass intended access controls.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive information due to DNS rebinding, potentially violating data protection requirements under GDPR and HIPAA. Exposure of internal network targets may result in unauthorized data disclosure, impacting compliance with confidentiality and security controls.

Mitigation Strategies

Immediately upgrade IBM ContextForge MCP Gateway to version 1.0.7 or higher. Restrict tool creation permissions to trusted users as a temporary measure. Monitor network traffic for suspicious outbound requests and review DNS resolution logs for anomalies.

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