CVE-2025-53539
7.5 · HIGHOverview
CVE-2025-53539 is a high-severity vulnerability affecting fastapi-guard fastapi_guard. It was published on July 7, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from fastapi-guard. Update fastapi_guard to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| fastapi-guard | fastapi_guard | >= 0, < 3.0.1 | Affected |
Frequently Asked Questions
What is CVE-2025-53539?
CVE-2025-53539 is a high-severity vulnerability affecting fastapi-guard fastapi_guard. It was published on July 7, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2025-53539?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-53539?
Check the references section for vendor advisories and patches from fastapi-guard. Update fastapi_guard to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-53539?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-53539 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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