Starlette is a lightweight ASGI framework/toolkit. Prior to 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.
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History
Wed, 29 Oct 2025 11:00:00 +0000
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Wed, 29 Oct 2025 00:15:00 +0000
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Tue, 28 Oct 2025 21:15:00 +0000
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Tue, 28 Oct 2025 20:30:00 +0000
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| Description | Starlette is a lightweight ASGI framework/toolkit. Prior to 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. | |
| Title | Starlette vulnerable to O(n^2) DoS via Range header merging in starlette.responses.FileResponse | |
| Weaknesses | CWE-407 | |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2025-10-28T20:14:53.655Z
Updated: 2025-10-28T20:36:49.189Z
Reserved: 2025-10-20T19:41:22.742Z
Link: CVE-2025-62727
Updated: 2025-10-28T20:36:44.968Z
Status : Awaiting Analysis
Published: 2025-10-28T21:15:40.447
Modified: 2025-10-30T15:05:32.197
Link: CVE-2025-62727