PT-2026-51172 · Vllm · Vllm

Russellb · Published 2026-06-20 · Updated 2026-06-20 · CVE-2026-56340

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions vLLM versions 0.10.2 through 0.12.x

Description Multimodal embeddings processing lacks sparse tensor validation. Since PyTorch disables sparse tensor invariant checks by default, an attacker can submit crafted embedding requests containing malformed tensor indices, such as negative or out-of-bounds values, when the prompt-embeds feature is enabled. This can lead to crashes, resource exhaustion resulting in denial of service, or potential out-of-bounds/write-what-where memory corruption.

Recommendations Update to version 0.13.0 or later. As a temporary workaround, disable the prompt-embeds feature to minimize the risk of exploitation.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-56340

Affected Products

Vllm

References · 5

• https://github.com/vllm-project/vllm/security/advisories/GHSA-mcmc-2m55-j8jj · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-56340 · Security Note
• https://twitter.com/CVEnew/status/2068466533391642636 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2068475199670898831 · Twitter Post
• https://vulncheck.com/advisories/vllm-denial-of-service-via-unvalidated-multimodal-embeddings · Note