CVE-2026-71486

MEDIUM 4.3

vLLM: Derender endpoints decode caller-supplied GenerateResponse token IDs without output bounds

CVSS Score

4.3

EPSS Score

0.0%

EPSS Percentile

0th

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the /v1/completions/derender and /v1/chat/completions/derender endpoints accept caller-supplied GenerateResponse objects whose generate_responses, choices, token_ids, prompt_logprobs, logprobs.content, top_logprobs, and routed_experts structures are processed by OnlineDerenderer and tokenizer.decode before max_model_len, max_tokens, max_num_seqs, or response-size limits are enforced, allowing an authenticated API client to consume excessive CPU and memory and produce oversized responses. This issue is fixed in version 0.26.0.

CWE	CWE-400 CWE-770
Vendor	vllm-project
Product	vllm
Published	Aug 17, 2026

Stay Ahead of the Next One

Get instant alerts for vllm-project vllm

Be the first to know when new medium vulnerabilities affecting vllm-project vllm are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Affected Versions

vllm-project / vllm

< 0.26.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/vllm-project/vllm/security/advisories/GHSA-8737-qx52-hjff github.com: https://github.com/vllm-project/vllm/pull/47260 github.com: https://github.com/vllm-project/vllm/commit/8e61b646e2d157f9b93451fa048f9c8530c8a67b github.com: https://github.com/vllm-project/vllm/releases/tag/v0.26.0