Skip to main content
← All vulnerabilities
CVE-2025-46560GHSA-VC6M-HM49-G9QGPYSEC-2026-2022

vLLM phi4mm: Quadratic Time Complexity in Input Token Processing​ leads to denial of service

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.8.5
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Versions starting from 0.8.0 and prior to 0.8.5 are affected by a critical performance vulnerability in the input preprocessing logic of the multimodal tokenizer. The code dynamically replaces placeholder tokens (e.g., <|audio_|>, <|image_|>) with repeated tokens based on precomputed lengths. Due to ​​inefficient list concatenation operations​​, the algorithm exhibits ​​quadratic time complexity (O(n²))​​, allowing malicious actors to trigger resource exhaustion via specially crafted inputs. This issue has been patched in version 0.8.5.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • vllm-project vllm

    From 0.8.0 · fixed in 0.8.5

  • vllmPyPI

    From 0.8.0 · fixed in 0.8.5

References 2

GitHub · vllm-project/vllm