Vulnerability · Published May 29, 2025 · Assigned by GitHub_M
CVE-2025-46570vLLM’s Chunk-Based Prefix Caching Vulnerable to Potential Timing Side-Channel
Low 2.6
In plain English
A low-severity security flaw in vllm from vllm-project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vllm | 0.9.0 | GHSA-4qjh-9fv9-r85r |
| PyPI | vllm | 0.9.0 | PYSEC-2025-53 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| vllm-project | vllm | < 0.9.0 |
Weakness: CWE-208 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N
References
- https://github.com/vllm-project/vllm/security/advisories/GHSA-4qjh-9fv9-r85r x_refsource_CONFIRM
- https://github.com/vllm-project/vllm/pull/17045 x_refsource_MISC
- https://github.com/vllm-project/vllm/commit/77073c77bc2006eb80ea6d5128f076f5e6c6f54f x_refsource_MISC