High
vLLM: Security Check Bypass via assert Statement in Activation Function Loading Allows Arbitrary Code Execution
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-41523
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 04:07 UTC · Revision 1
Source evidence
vLLM: Security Check Bypass via assert Statement in Activation Function Loading Allows Arbitrary Code Execution
core-osv · Original sourcePublished 22 Jun 2026, 22:18 UTC
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.
osv:CVE-2026-41523
Complete source record
{
"id": "88f505625ac4d54e42c9d285600e4d73b8bdbd83d65edde37c602d51ff6834f8",
"url": "https://osv.dev/vulnerability/CVE-2026-41523",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "vLLM: Security Check Bypass via assert Statement in Activation Function Loading Allows Arbitrary Code Execution",
"summary": "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.",
"evidence": "osv:CVE-2026-41523",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-41523",
"aliases": [
"CVE-2026-41523",
"GHSA-q8gq-377p-jq3r",
"PYSEC-2026-2300"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
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{
"repo": "https://github.com/vllm-project/vllm",
"type": "GIT",
"events": [
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{
"fixed": "0b3ba88f165976e77ca5e6a7a3f5bba4562b80af"
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"source": "CPE_RANGE"
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{
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],
"source": "REFERENCES_COMMIT"
}
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"submission"
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"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-41523.json"
}
}
],
"modified": "2026-10-28T02:30:33.089544597Z",
"provider": "osv",
"references": [
"https://huntr.com/bounties/dcb05b04-e625-41e7-adbc-bbae0cc2d64c",
"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41523.json",
"https://access.redhat.com/errata/RHSA-2026:36005",
"https://access.redhat.com/errata/RHSA-2026:36006",
"https://access.redhat.com/errata/RHSA-2026:57380",
"https://access.redhat.com/errata/RHSA-2026:57387",
"https://access.redhat.com/errata/RHSA-2026:57389",
"https://access.redhat.com/errata/RHSA-2026:57390",
"https://access.redhat.com/errata/RHSA-2026:59138",
"https://access.redhat.com/errata/RHSA-2026:59139",
"https://access.redhat.com/errata/RHSA-2026:59144",
"https://access.redhat.com/errata/RHSA-2026:59151",
"https://access.redhat.com/errata/RHSA-2026:61627",
"https://access.redhat.com/errata/RHSA-2026:61629",
"https://access.redhat.com/errata/RHSA-2026:62335",
"https://access.redhat.com/errata/RHSA-2026:62336",
"https://access.redhat.com/security/cve/CVE-2026-41523",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41523.json",
"https://github.com/vllm-project/vllm/security/advisories/GHSA-q8gq-377p-jq3r",
"https://nvd.nist.gov/vuln/detail/CVE-2026-41523",
"https://bugzilla.redhat.com/show_bug.cgi?id=2491582",
"https://github.com/vllm-project/vllm/commit/b3c7ffcab82c2439726f8cb213800f6f38c023d3"
],
"provider_metadata": {
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"CWE-94"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41523.json"
}
},
"related_cves": [
{
"value": "CVE-2026-41523",
"evidence": "/id"
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"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 500228,
"published_at": "2026-06-22T22:18:14.494+00:00"
}