CVE-2025-53539: medium-severity vulnerability in rennf93 fastapi-guard
ReDoS in fastapi-guard's penetration attempts detector
Published
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.9epss 0.5%
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.
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
Affected products
rennf93 · fastapi-guardRelated CVEs — rennf93 fastapi-guard
In the same product, most dangerous first.