# CVE-2026-102894: GPUStack: SAML callback trusts an unverified SAMLResponse, allowing authentication bypass and account takeover

Status: published. Published: 2026-11-04. Updated: 2026-11-06.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- gpustack / gpustack: >= 0.7.1, < 2.2.2 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 9.1 (critical); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N; source: CNA: GitHub_M

- CVSS 3.1: 9.1 (critical); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.26% as of 2026-11-05; percentile 17.63%

- SSVC: exploitation none; automatable yes; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-294, CWE-347

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/gpustack/gpustack/security/advisories/GHSA-62m9-f875-rqw6 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/gpustack/gpustack/pull/5753 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/gpustack/gpustack/pull/5923 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/gpustack/gpustack/commit/705edbe1b5feec63959306daecd640e1c70eced2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/gpustack/gpustack/commit/adc6d82be34e48390720a1361df616e2ea9d6d45 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/gpustack/gpustack/releases/tag/v2.2.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/gpustack/gpustack/commit/705edbe1b5feec63959306daecd640e1c70eced2 (security-advisories@github.com)

- https://github.com/gpustack/gpustack/commit/adc6d82be34e48390720a1361df616e2ea9d6d45 (security-advisories@github.com)

- https://github.com/gpustack/gpustack/pull/5753 (security-advisories@github.com)

- https://github.com/gpustack/gpustack/pull/5923 (security-advisories@github.com)

- https://github.com/gpustack/gpustack/releases/tag/v2.2.2 (security-advisories@github.com)

- https://github.com/gpustack/gpustack/security/advisories/GHSA-62m9-f875-rqw6 (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-102894; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102894; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-102894; retrieved 2026-11-06; source updated Not reported

Revision: b2ae12faa054821b925ee6ef2aff74fe0b703be92cb99d778f45e25f73f6c441

Canonical: https://y2.dev/cve/CVE-2026-102894

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