P4Verified

CVE-2025-62727: starlette >= 0.39.0, < 0.49.1

CVE-2025-62727. CVSS 3.1 base score 7.5 (HIGH, Vendor/CNA). EPSS 0.00684 (percentile 0.5097), scored 2026-10-06.

Affected technology

starlette · >= 0.39.0, < 0.49.1
Kludex

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · No privileges required · No user interaction required

What an attacker can do

An unauthenticated attacker can send a crafted HTTP Range header that triggers quadratic-time processing in Starlette's FileResponse Range parsing/merging logic. Vendor/CNA’s CVSS 3.1 assessment (base score 7.5/10) rates confidentiality and integrity impact as none; availability impact as high.

Published 2026-10-08 17:34:52.231344+00:00

CWE: CWE-407
CCR priority: 30.2 /100 (P4)
CVSS 3.1: 7.5 /10 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · Vendor/CNA
EPSS: 0.00684 · percentile 0.51074 · 2026-10-08
KEV: no

Provenance

FIRST EPSS daily exploit-probability · Source record · observed 2026-10-08 17:36:22.845483+00:00 UTC
NVD CVE API 2.0 · Source record · observed 2026-10-08 17:32:11.049884+00:00 UTC

Stable permalink: https://cybercodered.org/item/cve-cve-2025-62727.html