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Vulnerability Intelligence Report
ContextForge: DNS TOCTOU race condition causes SSRF protection bypass (`/admin/gateways/test`)

CVE-2026-53708

ContextForge is an AI gateway, registry, and proxy that provides centralized discovery, guardrails, and management for MCP, A2A, and REST or gRPC APIs. Prior to 1.0.3, the /admin/gateways/test call site in mcpgateway/admin.py calls validate_gateway_test_url() in mcpgateway/common/validators.py to resolve and reject private, loopback, link-local, and cloud-metadata addresses, but ResilientHttpClient later resolves the original hostname again without binding the validated address. When MCPGATEWAY_ADMIN_API_ENABLED is enabled, an attacker with a database-backed role containing explicit gateways.read permission can use DNS rebinding to return a public address during validation and a private or metadata address during connection, bypassing ssrf_blocked_networks and ssrf_dns_fail_closed because those controls apply only to the validation-time result. The endpoint's allow_admin_bypass=False setting means a bootstrap-only virtual platform-admin identity without a database role is not sufficient. Successful exploitation can reach internal services and cloud metadata, expose cloud credentials, access internal APIs, or probe internal network ports. This issue is fixed in version 1.0.3.

No Active Exploit Signals
CVSS Base Score
6.6
MEDIUM
Exploitability:1.4
Impact Score:4.8
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
Authentication
Weaponization
SSVC Action

Weaknesses (CWE)

CWE-350 ↗CWE-350: Reliance on Reverse DNS Resolution for a Security-Critical Action
CWE-367 ↗CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CWE-918 ↗CWE-918: Server-Side Request Forgery (SSRF)

Affected Products & Versions

Vendor Product Affected Versions
IBM mcp-context-forge < 1.0.3 (affected)
IBM mcp-contextforge-gateway < 1.0.3 (affected)

References & Technical Advisories

No reference links found.

Threat Intelligence Signals

Identity & Timeline

StatusPUBLISHED
Assigning AuthorityGitHub, Inc. · Vendor · USA
Reserved2026-06-10T16:43:31
Published2026-09-14T15:56:53
Last Updated2026-09-14T16:33:41

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