Hacking, PenTest, and Cybersecurity Tools for Your Security Arsenal!

Loading CVE intelligence

Loading vulnerability catalog

Kitploit is a directory of hacking, cybersecurity, and pentesting tools. Discover the latest project updates to find vulnerabilities, analyze systems, automate testing, and strengthen your security.

Tool Directory

CVE-2025-62727

HighPublished

Starlette vulnerable to O(n^2) DoS via Range header merging in starlette.responses.FileResponse

Published: Oct 28, 2025
Updated: Nov 4, 2025
Assigning CNA: GitHub_M
Evidence observed: Aug 25, 2026

Primary CVSS

7.5/ 10High

nvd · CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS probability estimate

0.6%

Low · next 30 days

Percentile: 48.8%
Model date: Sep 21, 2026

EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.

Summary

Starlette is a lightweight ASGI framework/toolkit. Starting in version 0.39.0 and prior to version 0.49.1 , an unauthenticated attacker can send a crafted HTTP Range header that triggers quadratic-time processing in Starlette's FileResponse Range parsing/merging logic. This enables CPU exhaustion per request, causing denial‑of‑service for endpoints serving files (e.g., StaticFiles or any use of FileResponse). This vulnerability is fixed in 0.49.1.

Sources

CVE-2025-62727-DemoPoC
Proof of concept of CVE-2025-62727 that can cause denial-of-service in FastAPI (based Starlette <= 0.48.0)

Responsible use

Use vulnerability information only on systems you own or are authorized to test. Kitploit links to public research metadata and does not store exploit code or malicious payloads.