Vulnerability in Fastapi-Guard Fastapi Guard

CVE-2025-46814

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.4 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-46814: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-46814?
CVE-2025-46814 is a low-severity vulnerability in Fastapi-Guard Fastapi Guard, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 3.4/10. Published 2025-05-06.
How severe is CVE-2025-46814?
Low severity. CVSS v3 base score is 3.4 out of 10.
Is CVE-2025-46814 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.