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CVE-2025-535396.9MediumCWE-1333

CVE-2025-53539: ReDoS in fastapi-guard's penetration attempts detector

rennf93 · fastapi-guard

Affected: rennf93 fastapi-guard · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days
42nd percentile
050100

Higher than 42% of scored CVEs

6.9MediumCVSS 4.0
LowMedium

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

  • rennf93 · fastapi-guard< 3.0.1

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas
Exploitation
Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV
Not listed
Public check
No public nuclei template
Published
July 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-53539 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References