Vulnerability in Fastapi-guard Fastapi_guard
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 attempts detection uses regex to scan incoming requests. However, some of t…
Vulnerability class: ReDoS (Regular Expression Denial of Service)
EPSS: 0.004 (33.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Fastapi-guard Fastapi_guard
- Rennf93 Fastapi-guard — versions < 3.0.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-53539?
- CVE-2025-53539 is a high-severity vulnerability in Fastapi-guard Fastapi_guard, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2025-07-07.
- How severe is CVE-2025-53539?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-53539 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.