CVE-2025-25183

vLLM using built-in hash() from Python 3.12 leads to predictable hash collisions in vLLM prefix cache

Description

vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Maliciously constructed statements can lead to hash collisions, resulting in cache reuse, which can interfere with subsequent responses and cause unintended behavior. Prefix caching makes use of Python's built-in hash() function. As of Python 3.12, the behavior of hash(None) has changed to be a predictable constant value. This makes it more feasible that someone could try exploit hash collisions. The impact of a collision would be using cache that was generated using different content. Given knowledge of prompts in use and predictable hashing behavior, someone could intentionally populate the cache using a prompt known to collide with another prompt in use. This issue has been addressed in version 0.7.2 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Category

2.6
CVSS
Severity: Low
CVSS 3.1 •
EPSS 0.02%
Vendor Advisory github.com
Affected: vllm-project vllm
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2025-25183?
CVE-2025-25183 has been scored as a low severity vulnerability.
How to fix CVE-2025-25183?
To fix CVE-2025-25183, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-25183 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-25183 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-25183?
CVE-2025-25183 affects vllm-project vllm.
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