CVE-2026-48710

{"id": "CVE-2026-48710", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.5, "exploitabilityScore": 3.9}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.5, "exploitabilityScore": 3.9}]}, "published": "2026-05-26T22:16:44.020", "references": [{"url": "https://badhost.org", "tags": ["Mitigation", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr", "tags": ["Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml", "tags": ["Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette", "tags": ["Mitigation", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://www.secwest.net/starlette", "tags": ["Exploit", "Mitigation", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette", "tags": ["Exploit", "Mitigation", "Third Party Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-444"}]}], "descriptions": [{"lang": "en", "value": "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 \u00a73.2 / RFC 3986 \u00a73.2.2 when constructing `request.url` and falls back to `scope[\"server\"]` for malformed values."}], "lastModified": "2026-06-03T02:14:40.100", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:encode:starlette:*:*:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "4C7C6045-86A6-4FAC-AE15-B12438E9D1B4", "versionEndExcluding": "1.0.1", "versionStartIncluding": "0.8.3"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}