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VulnerabilityPublished

CVE-2026-53708: ContextForge · DNS TOCTOU race condition causes SSRF protection bypass (`/admin/gateways/test`)

Affects mcp-contextforge-gatewaySource GCVE Database

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Authoritative record:CVE-2026-53708· Medium 6.6

Not known to be exploited · CVSS 6.6 Medium : upgrade to 1.0.3 when convenient.

Data as of 13 Nov 2026, 23:54 UTC

CVSS 3.1 base score
6.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.0.3
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:N

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 14 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: evidence found.

    CISA SSVC: proof of concept public

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by GitHub, Inc.

    , 96 days before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. CISA SSVC assessment

    proof of concept public

    , 36 minutes after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 14 Nov 2026.

What to do

Upgrade mcp-contextforge-gateway to 1.0.3.

Affected software

ProductAffectedFixed in
PyPImcp-contextforge-gatewayAffected
  • <1.0.3
Fixed in
  • 1.0.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available for this vulnerability. Operators should upgrade to a fixed version to eliminate the DNS TOCTOU race condition. Until patched, mitigation requires ensuring MCPGATEWAY_ADMIN_API_ENABLED is not enabled unless necessary and strictly controlling credentials with gateways.read permission. The vendor acknowledges the limitation and tracks it for future improvement; thus, applying the official fix is recommended. No temporary workaround is described in the advisory.

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.

References

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