CVE-2025-53539 — ReDoS in fastapi-guard's penetration attempts detector
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 dete…
Published: 2025-07-07 · CVSS: 6.9 · CVSS 4.0
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: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7