CVE-2026-73558: vLLM: Cross-User Data Leak Vulnerability

Published Aug 13, 2026
·
Updated

vLLM is an inference and serving engine for large language models. Prior to 0.27.0, an integer overflow in blockIdx.x 2 d in activationkernels.cu can cause actandmulkernel to consume another batched user's input, allowing a request processed in the same inference batch to receive a partial or complete copy of another user's inference result. This issue is fixed in version 0.27.0.

Affected Software

1 affected component
vllm<0.27.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade vLLM to a version that resolves this vulnerability.

    Fixed in 0.27.0

Event History

Aug 13, 2026
CVE Published
via MITRE·03:06 PM
Data Sourced
via MITRE·03:06 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2026-73558?

CVE-2026-73558 has a medium severity score of 5.3.

2

What does CVE-2026-73558 entail?

CVE-2026-73558 describes a cross-user data leak vulnerability in vLLM due to an integer overflow issue.

3

How do I fix CVE-2026-73558?

To fix CVE-2026-73558, upgrade your vLLM software to version 0.27.0 or later.

4

What impact does CVE-2026-73558 have on data security?

CVE-2026-73558 can lead to unintended exposure of another user's data during the inference process.

5

Is CVE-2026-73558 related to specific software?

Yes, CVE-2026-73558 specifically affects the vLLM inference and serving engine for large language models.

Contact

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CVE-2026-73558 - vLLM: Cross-User Data Leak Vulnerability - SecAlerts