CVE-2025-53539

Published Jul 7, 2025

Last updated 10 days ago

CVSS medium 6.9

Overview

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.
Source
security-advisories@github.com
NVD status
Awaiting Analysis

Risk scores

CVSS 4.0

Type
Secondary
Base score
6.9
Impact score
-
Exploitability score
-
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-1333

Social media

Hype score
Not currently trending

  1. CVE-2025-53539 FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. fastapi-guard's penetration at… https://t.co/nRfmb4HXCN

    @CVEnew

    7 Jul 2025

    376 Impressions

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References

Sources include official advisories and independent security research.