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.
References
| Link | Resource |
|---|---|
| https://github.com/rennf93/fastapi-guard/commit/d9d50e8130b7b434cdc1b001b8cfd03a06729f7f | Patch |
| https://github.com/rennf93/fastapi-guard/security/advisories/GHSA-j47q-rc62-w448 | Exploit Vendor Advisory |
Configurations
History
31 Dec 2025, 17:05
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.5 |
| CPE | cpe:2.3:a:fastapi-guard:fastapi_guard:*:*:*:*:*:*:*:* | |
| References | () https://github.com/rennf93/fastapi-guard/commit/d9d50e8130b7b434cdc1b001b8cfd03a06729f7f - Patch | |
| References | () https://github.com/rennf93/fastapi-guard/security/advisories/GHSA-j47q-rc62-w448 - Exploit, Vendor Advisory | |
| First Time |
Fastapi-guard fastapi Guard
Fastapi-guard |
08 Jul 2025, 16:18
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
07 Jul 2025, 20:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-07-07 20:15
Updated : 2025-12-31 17:05
NVD link : CVE-2025-53539
Mitre link : CVE-2025-53539
CVE.ORG link : CVE-2025-53539
JSON object : View
Products Affected
fastapi-guard
- fastapi_guard
CWE
CWE-1333
Inefficient Regular Expression Complexity
