Staging Environment: Content and features may be unstable or change without notice.
Advisory details: pysec / PYSEC-2025-50
Advisory ID pysec/PYSEC-2025-50
Aliases CVE-2025-48887
GHSA-w6q7-j642-7c25
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
There are no known severity scores.
Reference id Reference type URL
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
GHSA-w6q7-j642-7c25 https://github.com/advisories/GHSA-w6q7-j642-7c25
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
There are no known vectors.

Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-05-30T17:58:00Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2025/48xxx/CVE-2025-48887.json

Source Advisory: vulnrichment/CVE-2025-48887

View SSVC decision tree 
[{'Exploitation': 'poc'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]