CVE-2025-48887: vllm — Exploit & Fix

Description

vLLM, an inference and serving engine for large language models (LLMs), has a Regular Expression Denial of Service (ReDoS) vulnerability in the file `vllm/entrypoints/openai/tool_parsers/pythonic_tool_parser.py` of versions 0.6.4 up to but excluding 0.9.0. The root cause is the use of a highly complex and nested regular expression for tool call detection, which can be exploited by an attacker to cause severe performance degradation or make the service unavailable. The pattern contains multiple nested quantifiers, optional groups, and inner repetitions which make it vulnerable to catastrophic backtracking. Version 0.9.0 contains a patch for the issue.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-1333 CWE-1333

Affected Products

Vendor	Product	Versions
vllm	vllm	0.6.4 — 0.9.0

References

Advisories & Patches

https://github.com/vllm-project/vllm/commit/4fc1bf813ad80172c1db31264beaef7d93fe0601 https://github.com/vllm-project/vllm/pull/18454 https://github.com/vllm-project/vllm/security/advisories/GHSA-w6q7-j642-7c25 https://github.com/vllm-project/vllm/security/advisories/GHSA-w6q7-j642-7c25

Exploits

https://github.com/vllm-project/vllm/security/advisories/GHSA-w6q7-j642-7c25 https://github.com/vllm-project/vllm/security/advisories/GHSA-w6q7-j642-7c25

Frequently Asked Questions

What is CVE-2025-48887? +

vLLM, an inference and serving engine for large language models (LLMs), has a Regular Expression Denial of Service (ReDoS) vulnerability in the file `vllm/entrypoints/openai/tool_parsers/pythonic_tool_parser.py` of versions 0.6.4 up to but excluding 0.9.0. The root cause is the use of a highly complex and nested regular expression for tool call detection, which can be exploited by an attacker to cause severe performance degradation or make the service unavailable. The pattern contains multiple nested quantifiers, optional groups, and inner repetitions which make it vulnerable to catastrophic backtracking. Version 0.9.0 contains a patch for the issue. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2025-48887? +

CVE-2025-48887 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-48887? +

CVE-2025-48887 affects products from vllm, specifically: vllm. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-48887? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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