{"cve":{"cve_id":"CVE-2026-48710","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.01384,"epss_percentile":0.6866,"epss_as_of":"2026-06-23","description":"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.","published_at":"2026-05-26T21:54:54.393000Z","last_modified_at":null,"cvss_v3_score":6.5,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-444","CWE-1289"],"nvd_references":["https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr","https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6","https://badhost.org","https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml","https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette","https://www.secwest.net/starlette","https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:30:44.057552Z"},"effective_severity":"MEDIUM","badges":["poc"],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"L","value_label":"Low"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"kludex","vendor_name":"Kludex","product_slug":"starlette","product_name":"starlette","version_start":"< 1.0.1","version_start_inclusive":true,"version_end":"< 1.0.1","version_end_inclusive":true,"cpe23_uri":"cve5:kludex:starlette:< 1.0.1:< 1.0.1"}],"exploit_refs":[{"source":"nuclei","kind":"nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-48710.yaml","title":"Starlette - Improper Validation of Unsafe Equivalence in Input","author":"ritikchaddha","disclosed_at":null}],"news":[],"references":[{"url":"https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6","source_type":"PATCH","tags":["patch"]},{"url":"https://badhost.org","source_type":"MISC","tags":[]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette","source_type":"MISC","tags":[]},{"url":"https://www.secwest.net/starlette","source_type":"MISC","tags":[]},{"url":"https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-05-26T21:54:54.393000Z","label":"CVE published","source":null},{"type":"poc_available","at":"2026-06-24T00:29:48.638073Z","label":"Public PoC available","source":"nuclei"},{"type":"cvss_changed","at":"2026-06-28T17:55:03.830140Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:03.830140Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:03.830140Z","label":"CVSS score revised","source":"cvelistv5"}]}