Vulnerability Intelligence Report
GPUStack: SAML callback trusts an unverified SAMLResponse, allowing authentication bypass and account takeover
CVE-2026-102894
GPUStack is an open-source GPU cluster manager for AI model serving and GPU instance provisioning. From 0.7.1 until 2.2.2, the /auth/saml/callback endpoint decoded SAML XML, used its NameID and attributes to resolve or provision a user, and minted a gpustack_session JWT without calling OneLogin_Saml2_Auth.process_response to verify the signature, issuer, audience, destination, or time conditions. Any network client could submit an identity for an existing user, including an administrator, or provision a new non-administrator account, even when SAML was not configured. Response and Assertion identifiers were not consumed, so captured signed responses could also be replayed. This issue is fixed in version 2.2.2.
No Active Exploit Signals
CVSS Base Score
9.1
CRITICAL
Exploitability:3.9
Impact Score:5.2
EPSS Probability:0.26%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-294 ↗CWE-294: Authentication Bypass by Capture-replay
CWE-347 ↗CWE-347: Improper Verification of Cryptographic Signature
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| gpustack | gpustack | >= 0.7.1, < 2.2.2 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.259%
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GitHub, Inc. · Vendor · USA |
| Reserved | 2026-09-29T17:34:42 |
| Published | 2026-11-04T21:18:29 |
| Last Updated | 2026-11-06T11:34:16 |
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