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Fencer Vulns
critical 9.8

CVE-2026-53709 json

MCP Context Forge: Hardcoded default JWT_SECRET_KEY shipped in source and .env.example enables pre-authentication platform admin token forgery

published 2026-10-13 26 d ago modified 2026-10-16 23 d ago also EUVD-2026-98769

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

MCP Context Forge is an MCP gateway and administrative platform. Prior to 1.0.2, mcpgateway/config.py and .env.example ship a known JWT_SECRET_KEY, while verify_jwt_token() accepts HS256 tokens signed with that key and get_current_user() creates a platform administrator when the token subject matches PLATFORM_ADMIN_EMAIL and REQUIRE_USER_IN_DB is false. A remote unauthenticated attacker can therefore mint accepted administrator tokens without a database account. While the vulnerable signing key remains configured and the platform-admin bootstrap remains enabled, forged access survives password rotation, account deletion, and session revocation, allowing administrative disclosure, modification, and service disruption. This issue is fixed in version 1.0.2.

Patch / fix

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • IBM mcp-context-forge

Classification

Weakness
  • CWE-287 Improper Authentication
  • CWE-321 Use of Hard-coded Cryptographic Key
  • CWE-798 Use of Hard-coded Credentials
  • CWE-1188 Initialization of a Resource with an Insecure Default

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.