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CVE-2025-62727

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

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Kludex / starletteaffected >= 0.39.0, < 0.49.1

CWE

CWE-407

References

ADP enrichment

CISA-ADP

No English description supplied.