Improper Validation of Array Index in vLLM - #VU128251
Published: April 27, 2026
Vulnerability identifier: #VU128251
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-129
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: vLLM
Affected software:
vLLM
vLLM
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper validation of array index in multimodal input position computation when processing text-only prompts containing special-token placeholders without matching image or video data. A remote user can send a specially crafted request to cause a denial of service.
Only deployments serving vision-language models through OpenAI-compatible endpoints that accept raw user text are affected.
Remediation
Install security update from vendor's website.