Resource exhaustion in vLLM - #VU139885
Published: July 28, 2026
Vulnerability identifier: #VU139885
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the /v1/completions/derender and /v1/chat/completions/derender endpoints when decoding caller-supplied GenerateResponse token IDs without output bounds. A remote user can send a specially crafted derender request with oversized nested token_id lists to cause a denial of service.
In disaggregated deployments, the issue affects the CPU-only render frontend; when the render router is attached alongside generation, it affects the same OpenAI-compatible server process handling normal client traffic.
Affected software
vLLM
Remediation
Install security update from vendor's website.
vLLM - update to 0.26.1 rc0