vLLM’s Chunk-Based Prefix Caching Vulnerable to Potential Timing Side-Channel
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| vllm-project | vllm | affected |
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No data.
| Vendor | Product | Versions |
|---|---|---|
| Vllm-project | Vllm | — |
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2025-16189 | 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. |
Github GHSA |
GHSA-4qjh-9fv9-r85r | Potential Timing Side-Channel Vulnerability in vLLM’s Chunk-Based Prefix Caching |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.430% probability within 30 days)
| Type | Values Removed | Values Added |
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| First Time appeared |
Vllm
Vllm vllm |
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| Weaknesses | CWE-203 | |
| CPEs | cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Vllm
Vllm vllm |
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| References |
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| Metrics |
threat_severity
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threat_severity
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| Type | Values Removed | Values Added |
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| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | vLLM’s Chunk-Based Prefix Caching Vulnerable to Potential Timing Side-Channel | |
| Weaknesses | CWE-208 | |
| References |
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| Metrics |
cvssV3_1
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