{"id":"CVE-2025-62727","summary":"Starlette vulnerable to O(n^2) DoS via Range header merging in starlette.responses.FileResponse","details":"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.","aliases":["GHSA-7f5h-v6xp-fcq8"],"modified":"2026-05-11T00:26:13.095297882Z","published":"2025-10-28T20:14:53.655Z","related":["CGA-mwr9-whh6-3ppf","openSUSE-SU-2025:15696-1","openSUSE-SU-2026:10109-1"],"database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62727.json","cwe_ids":["CWE-407"]},"references":[{"type":"WEB","url":"https://github.com/Kludex/starlette/releases/tag/0.49.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62727.json"},{"type":"ADVISORY","url":"https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-62727"},{"type":"FIX","url":"https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5"},{"type":"FIX","url":"https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/kludex/starlette","events":[{"introduced":"0"},{"fixed":"4ea6e22b489ec388d6004cfbca52dd5b147127c5"}]},{"type":"GIT","repo":"https://github.com/kludex/starlette","events":[{"introduced":"0"},{"fixed":"69ed26a85956ef4bd0161807eb27abf49be7cd3c"}]},{"type":"GIT","repo":"https://github.com/kludex/starlette","events":[{"introduced":"0"},{"fixed":"7e4b7428f273dbdc875dcd036d20804bcfc7b2ee"}]}],"versions":["0.1.0","0.1.1","0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.10.0","0.10.1","0.10.4","0.11.1","0.11.2","0.11.3","0.11.4","0.12.0","0.12.0.b1","0.12.0.b2","0.12.0.b3","0.12.11","0.12.12","0.12.13","0.12.2","0.12.3","0.12.4","0.12.5","0.12.6","0.12.7","0.12.8","0.12.9","0.13.0","0.13.1","0.13.2","0.13.3","0.13.4","0.13.5","0.13.6","0.13.7","0.13.8","0.14.0","0.14.1","0.14.2","0.15.0","0.16.0","0.17.0","0.17.1","0.18.0","0.19.0","0.19.1","0.2.1","0.2.2","0.2.3","0.20.0","0.20.1","0.20.2","0.20.3","0.20.4","0.21.0","0.22.0","0.23.0","0.23.1","0.24.0","0.25.0","0.26.0","0.26.0.post1","0.26.1","0.27.0","0.28.0","0.29.0","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.30.0","0.31.0","0.31.1","0.32.0","0.32.0.post1","0.33.0","0.34.0","0.35.0","0.35.1","0.36.0","0.36.1","0.36.2","0.36.3","0.37.0","0.37.1","0.37.2","0.38.0","0.38.1","0.38.2","0.38.3","0.38.4","0.38.5","0.38.6","0.39.0","0.39.1","0.39.2","0.4.0","0.4.1","0.4.2","0.40.0","0.41.0","0.41.1","0.41.2","0.41.3","0.42.0","0.43.0","0.44.0","0.45.0","0.45.1","0.45.2","0.45.3","0.46.0","0.46.1","0.46.2","0.47.0","0.47.1","0.47.2","0.47.3","0.48.0","0.49.0","0.5.0","0.5.1","0.5.2","0.5.3","0.5.4","0.5.5","0.6.1","0.6.2","0.6.3","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.9.0","0.9.1","0.9.10","0.9.11","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","0.9.7","0.9.8","0.9.9"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-62727.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}