{"id":"UBUNTU-CVE-2025-62727","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.","modified":"2026-01-20T19:20:15.083763Z","published":"2025-10-28T21:15:00Z","upstream":["CVE-2025-62727"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-62727"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-62727"},{"type":"REPORT","url":"https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"},{"type":"REPORT","url":"https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5"}],"affected":[{"package":{"name":"starlette","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/starlette@0.18.0-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.14.1-1","0.16.0-1","0.18.0-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.18.0-1","binary_name":"python3-starlette"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-62727.json"}},{"package":{"name":"starlette","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/starlette@0.31.1-1?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30.0-1","0.31.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.31.1-1","binary_name":"python3-starlette"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-62727.json"}},{"package":{"name":"starlette","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/starlette@0.46.1-3?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.46.1-2","0.46.1-3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.46.1-3","binary_name":"python3-starlette"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-62727.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}