---
cve: "CVE-2026-56340"
severity: "HIGH"
cvss: 8.7
epss: "35%"
vendor: "vLLM"
kev: false
exploited: false
published: "2026-06-20 19:16:23"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-14T14:16:26+02:00"
---

# CVE-2026-56340

> 8.7 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 72506c98349d6bcd32b4e33eec7b5513453c1502 (Commit)

## Referenzen

- <https://github.com/vllm-project/vllm/security/advisories/GHSA-mcmc-2m55-j8jj>
- <https://www.vulncheck.com/advisories/vllm-denial-of-service-via-unvalidated-multimodal-embeddings>
- <https://access.redhat.com/security/cve/CVE-2026-56340>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2491060>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56340.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-56340) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_