CVE-2026-102894

Summary

The /auth/saml/callback endpoint in GPUStack (versions 0.7.1–2.2.2) accepted unverified SAML responses, allowing any attacker to forge authentication tokens for existing users—including administrators—or create new accounts—by submitting arbitrary SAML XML without signature, issuer, audience, or time validation.

Exploitability

Exploitation is trivial for any network-accessible attacker with no authentication required and no SAML configuration needed on the target.

Blast radius

An attacker can impersonate any user—including admins—leading to full account takeover, privilege escalation, and potential compromise of the entire GPU cluster management system.

Detection

Look for POST requests to /auth/saml/callback containing SAMLResponse parameters with malformed, missing, or unverifiable signatures in web server or application logs; repeated or identical SAMLResponse values from different source IPs may indicate replay attempts.

Prioritized remediation

Upgrade to GPUStack version 2.2.2 or later, which properly invokes OneLogin_Saml2_Auth.process_response to validate SAML assertions before minting session tokens.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.