What is CVE-2025-54365?

CVE-2025-54365 is a high-severity vulnerability in Fastapi-Guard Fastapi Guard, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2025-07-23.

How severe is CVE-2025-54365?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2025-54365 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in Fastapi-Guard Fastapi Guard

CVE-2025-54365

fastapi-guard is a security library for FastAPI that provides middleware to control IPs, log requests, detect penetration attempts and more. In version 3.0.1, the regular expression patched to mitigate the ReDoS vulnerability by limiting the length of string fails to catch inputs that exceed this limit. This type of patch fails to detect cases in which the string representing the attributes of a <script> tag exceeds 100 characters. As a result, most of the regex patterns present in version 3.0.1 can be bypassed. This is fixed in version 3.0.2.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2025-07-23 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.008 (53.7th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.000

Affected products

Fastapi-Guard Fastapi Guard — versions 3.0.1
Rennf93 Fastapi-Guard — versions >= 3.0.1, < 3.0.2

Weakness classification (CWE)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

github.com/rennf93/fastapi-guard/security/advisories/GHSA-rrf6-pxg8-684g (Exploit, Vendor Advisory)
github.com/rennf93/fastapi-guard/commit/0829292c322d33dc14ab00c5451c5c138148035a (Patch)
github.com/rennf93/fastapi-guard/commit/d9d50e8130b7b434cdc1b001b8cfd03a06729f7f (Patch)

Frequently asked questions

What is CVE-2025-54365?: CVE-2025-54365 is a high-severity vulnerability in Fastapi-Guard Fastapi Guard, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2025-07-23.
How severe is CVE-2025-54365?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-54365 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.