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High 7.5Published Jun 22, 2026

CVE-2026-41523vLLM: Security Check Bypass via assert Statement in Activation Function Loading Allows Arbitrary Code Execution

Updated under an hour ago ()

Does this affect you?

It affects vllm-project vllm and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

vLLM is an inference and serving engine for large language models (LLMs). Prior to 0.22.0, an assert-based security check in vLLM's activation function loading allows any unauthenticated attacker to achieve arbitrary code execution on the server by publishing a malicious HuggingFace model, when vLLM runs in Python optimized mode (python -O or PYTHONOPTIMIZE=1). This vulnerability is fixed in 0.22.0.

CVSS
7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-94, CWE-617
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Modified
Record last updated
Sep 4, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
vllm-project vllm
vllm_project:vllm (from the name)
before 0.22.0
CNA record
Red Hat Red Hat AI Inference Server 3.2
redhat:ai_inference_server
from 1782951012 not affected; from 1787860580 not affected
CISA ADP
Red Hat Red Hat Enterprise Linux AI 3.3
redhat:enterprise_linux_ai
from 1788290314 not affected
CISA ADP
Versions not stated
CISA ADP
vllm vllm
vllm:vllm
before 0.22.0
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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