CVE-2025-25183

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

Severity Score

2.6

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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.

*Credits: N/A

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

High

Authentication

Single

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2025-02-03 CVE Reserved
2025-02-07 CVE Published
2025-02-12 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-354: Improper Validation of Integrity Check Value

CAPEC

References (3)

URL	Tag	Source
https://github.com/python/cpython/commit/432117cd1f59c76d97da2eaff55a7d758301dbc7	X_refsource_misc
https://github.com/vllm-project/vllm/pull/12621	X_refsource_misc
https://github.com/vllm-project/vllm/security/advisories/GHSA-rm76-4mrf-v9r8	X_refsource_confirm

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Vllm-project Search vendor "Vllm-project"		Vllm Search vendor "Vllm-project" for product "Vllm"				< 0.7.2 Search vendor "Vllm-project" for product "Vllm" and version " < 0.7.2"		en		Affected