vLLM — Vulnerability (CVE-2025-46570)
Date: 2025-05
Affected: vllm/vllm
Attack vector: other
Category: vulnerability-disclosure
Severity: Low
CVE: CVE-2025-46570
CWE: CWE-203
CWE-208
CVSS: 2.6 (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N)

vLLM is an inference and serving engine for large language models (LLMs). Prior to version 0.9.0, when a new prompt is processed, if the PageAttention mechanism finds a matching prefix chunk, the prefill process speeds up, which is reflected in the TTFT (Time to First Token). These timing differences caused by matching chunks are significant enough to be recognized and exploited. This issue has been patched in version 0.9.0.


Mitigations:

Architectural layers (MAESTRO):