PT-2025-28250 · Unknown · Fastapi Guard

Cycloctane · Published 2025-07-07 · Updated 2025-12-31 · CVE-2025-53539

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions: FastAPI Guard versions prior to 3.0.1

Description: The issue concerns the penetration attempts detection mechanism in FastAPI Guard, which utilizes regex patterns to scan incoming requests. However, some of these regex patterns are inefficient and can lead to polynomial complexity backtracks when handling specially crafted inputs.

Recommendations: For versions prior to 3.0.1, update to version 3.0.1 to resolve the issue.

Exploit

Fix

DoS

Weakness Enumeration

CWE-1333

Related Identifiers

BDU:2025-08270

CVE-2025-53539

GHSA-J47Q-RC62-W448

Affected Products

Fastapi Guard

References · 11

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53539.json · Exploit
• https://github.com/rennf93/fastapi-guard/security/advisories/GHSA-j47q-rc62-w448 · Vendor Advisory
• https://github.com/rennf93/fastapi-guard/commit/d9d50e8130b7b434cdc1b001b8cfd03a06729f7f · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2025-53539 · Security Note
• https://osv.dev/vulnerability/GHSA-j47q-rc62-w448 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-53539 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-08270 · Security Note
• https://github.com/rennf93/fastapi-guard · Note
• https://t.me/cveNotify/147349 · Telegram Post
• https://github.com/advisories/GHSA-j47q-rc62-w448 · Note
• https://twitter.com/CVEnew/status/1942305758839783465 · Twitter Post