CVE-2025-46560
vLLM phi4mm: Quadratic Time Complexity in Input Token Processing​ leads to denial of service
MEDIUM 6.5
At a glance
- Source
- NVD
- EPSS
- EPSS 0.52 % · percentile 44 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-1333 — Inefficient Regular Expression Complexity
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-vc6m-hm49-g9qg — vLLM: Quadratic Time Complexity in Input Token Processing​ leads to denial of service
- PYSEC-2026-2022 — phi4mm: Quadratic Time Complexity in Input Token Processing​ leads to denial of service
European references
- ENISA EUVD · EUVD-2025-12671
- GCVE · GCVE-0-2025-46560
Affected configurations (NVD CPE)
cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*≥ 0.8.0 < 0.8.5
Affected products
| Product | Versions |
|---|---|
| vllm-project · vllm | affected >= 0.8.0, < 0.8.5 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |