FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. fastapi-guard's penetration attempts detection uses regex to scan incoming requests. However, some of the regex patterns used in detection are extremely inefficient and can cause polynomial complexity backtracks when handling specially crafted inputs. This vulnerability is fixed in 3.0.1.
History

Mon, 07 Jul 2025 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 07 Jul 2025 19:30:00 +0000

Type Values Removed Values Added
Description FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. fastapi-guard's penetration attempts detection uses regex to scan incoming requests. However, some of the regex patterns used in detection are extremely inefficient and can cause polynomial complexity backtracks when handling specially crafted inputs. This vulnerability is fixed in 3.0.1.
Title ReDoS in fastapi-guard's penetration attempts detector
Weaknesses CWE-1333
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-07-07T19:16:02.559Z

Updated: 2025-07-07T20:51:58.541Z

Reserved: 2025-07-02T15:15:11.515Z

Link: CVE-2025-53539

cve-icon Vulnrichment

Updated: 2025-07-07T20:51:49.329Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-07-07T20:15:28.027

Modified: 2025-07-08T16:18:34.923

Link: CVE-2025-53539

cve-icon Redhat

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