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CVE-2026-58399GHSA-GFJ5-979R-92PW

@acastellon/auth has an authentication bypass via spoofable headers in validateToken()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.3.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • antonio-castellon module-auth

    fixed in 2.3.0

  • @acastellon/authnpm

    fixed in 2.3.0

References 3

GitHub · antonio-castellon/module-auth

npmjs.com