{"id":"UBUNTU-CVE-2026-48710","details":"Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the `Host` header against the grammar of RFC 9112 §3.2 / RFC 3986 §3.2.2 when constructing `request.url` and falls back to `scope[\"server\"]` for malformed values.","modified":"2026-09-03T22:54:55.324659440Z","published":"2026-05-26T22:16:00Z","upstream":["CVE-2026-48710"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-48710"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-48710"},{"type":"REPORT","url":"https://x41-dsec.de/lab/advisories/x41-2026-002-starlette/"},{"type":"REPORT","url":"https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr"},{"type":"REPORT","url":"https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6"},{"type":"REPORT","url":"https://github.com/Kludex/starlette/pull/3279"},{"type":"REPORT","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog"}],"affected":[{"package":{"name":"starlette","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/starlette?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_name":"python3-starlette","binary_version":"0.18.0-1"}],"priority_reason":"CISA-KEA"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48710.json"}},{"package":{"name":"starlette","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/starlette?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30.0-1","0.31.1-1"],"ecosystem_specific":{"priority_reason":"CISA-KEA","binaries":[{"binary_name":"python3-starlette","binary_version":"0.31.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48710.json"}},{"package":{"name":"starlette","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/starlette?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.46.1-2","0.46.1-3"],"ecosystem_specific":{"priority_reason":"CISA-KEA","binaries":[{"binary_name":"python3-starlette","binary_version":"0.46.1-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48710.json"}},{"package":{"name":"starlette","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/starlette?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.46.1-3","0.50.0-1"],"ecosystem_specific":{"priority_reason":"CISA-KEA","binaries":[{"binary_name":"python3-starlette","binary_version":"0.50.0-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48710.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"type":"Ubuntu","score":"high"}]}