CVE-2025-62727

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-62727
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.

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

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

No configuration.

History

04 Nov 2025, 18:16

Type Values Removed Values Added
Summary (en) 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. (en) 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.
References
  • () https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c -
  • () https://github.com/Kludex/starlette/releases/tag/0.49.1 -

28 Oct 2025, 21:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-10-28 21:15

Updated : 2025-11-04 18:16

NVD link : CVE-2025-62727

Mitre link : CVE-2025-62727

CVE.ORG link : CVE-2025-62727

JSON object : View

Products Affected

No product.

CWE
CWE-407

Inefficient Algorithmic Complexity