Medium severity · published Sep 14, 2026
CVE-2026-53708
ContextForge: DNS TOCTOU race condition causes SSRF protection bypass (`/admin/gateways/test`)
6.6
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
High
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 28% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
mcp-context-forge · IBM
< 1.0.3 · source: vendor
MC
mcp-contextforge-gateway · IBM
< 1.0.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53708
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53708
github.com
https://github.com/IBM/mcp-context-forge/commit/fba11a99babd80779fa05510b35fb6a153bbacaf
github.com
https://github.com/IBM/mcp-context-forge/releases/tag/v1.0.3
github.com
https://github.com/IBM/mcp-context-forge/security/advisories/GHSA-9hgc-g3w5-67cm
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