CVE-2025-62727

HIGH EPSS 46.0%
Published Oct 28, 20258mo ago · Modified Jun 17, 20261w ago
7.5 CVSS 3.1
High
Find Similar
Published Oct 28, 2025 8mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
46.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-407

References 4

  • github.com https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5
  • github.com https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c
  • github.com https://github.com/Kludex/starlette/releases/tag/0.49.1
  • github.com https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.