CVE-2026-58399

Summary

@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0.

Affected Software

VendorProductVersion RangeStatus
antonio-castellonmodule-auth< 2.3.0affected

Weaknesses

  • CWE-287: CWE-287: Improper Authentication

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: total

References