CVE-2026-58399
CVE-2026-58399 · @acastellon/auth has an authentication bypass via spoofable headers in validateToken()
This page contains facts from public vulnerability sources. Check the original advisory before updating.
@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.
CVSS 8.7 · High · EPSS 1.0% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
module-auth
- Versions
- < 2.3.0: Affected
No fix published
@acastellon/auth npm
- Affected ranges
- SEMVER: < 2.3.0
Update to 2.3.0