CVE-2026-56340 Details
Description
vLLM versions >= 0.10.2 and < 0.13.0 are missing sparse tensor validation in multimodal embeddings processing. Because PyTorch disables sparse tensor invariant checks by default, an attacker can submit crafted embedding requests with malformed (negative or out-of-bounds) tensor indices, when the prompt-embeds feature is enabled, to trigger crashes or resource exhaustion (denial of service), with potential for out-of-bounds/write-what-where memory corruption. This continues CVE-2025-62164, whose prior fix only disabled the feature by default rather than addressing the root cause.
A vulnerability in vLLM versions 0.10.2 through 0.13.0 allows for denial-of-service (DoS) attacks and potential memory corruption. The issue arises from the absence of proper validation for sparse tensors in multimodal embeddings. PyTorch, by default, disables certain invariant checks for sparse tensors, enabling attackers to send embedding requests with malformed indices. When the prompt-embeds feature is active, this can lead to crashes or resource exhaustion. This vulnerability builds upon CVE-2025-62164, which only partially addressed the issue by disabling the feature by default, rather than fixing the underlying problem.
Users can upgrade to vLLM version 0.13.0 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 24, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-20 | Improper Input Validation | [email protected] |
| CWE-787 | Out-of-bounds Write | redhat-SADP |
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| vllm vllm | >= 0.10.2, < 0.13.0 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 15, 2026 | CVE Modified | redhat-SADP |
| Jun 30, 2026 | CVE Modified | redhat-SADP |
| Jun 26, 2026 | Initial Analysis | [email protected] |
| Jun 24, 2026 | CVE Modified | CISA-ADP |
| Jun 20, 2026 | New CVE Received | [email protected] |