GPUStack up to 2.2.1 SAML Callback authentication replay

Summaryinfo

A vulnerability labeled as critical has been found in GPUStack up to 2.2.1. This affects an unknown function of the component SAML Callback. Such manipulation leads to authentication replay. This vulnerability is uniquely identified as CVE-2026-102894. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in GPUStack up to 2.2.1. It has been rated as critical. Affected by this issue is an unknown part of the component SAML Callback. The manipulation with an unknown input leads to a authentication replay vulnerability. Using CWE to declare the problem leads to CWE-294. A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-102894 since 09/29/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1040.

Upgrading to version 2.2.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• GPUStack

Version

• 2.2.0
• 2.2.1

Website

• Product: https://github.com/gpustack/gpustack/

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Once again VulDB remains the best source for vulnerability data.

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