{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-86205", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-05T11:52:36.822Z", "datePublished": "2026-09-06T12:00:25.530Z", "dateUpdated": "2026-09-06T12:00:25.530Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-06T12:00:25.530Z"}, "datePublic": "2026-03-21T00:00:00.000Z", "title": "h3 before 2.0.1-rc.18 Open Redirect via redirectBack()", "descriptions": [{"lang": "en", "value": "h3 versions before 2.0.1-rc.18 contain an open redirect vulnerability in the redirectBack() utility that fails to sanitize protocol-relative paths in the Referer header pathname. Attackers can craft a same-origin URL with a double-slash path segment that passes origin validation but produces a Location header interpreted by browsers as a protocol-relative redirect to an external domain."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "URL Redirection to Untrusted Site ('Open Redirect')", "cweId": "CWE-601", "type": "CWE"}]}], "affected": [{"vendor": "h3js", "product": "h3", "defaultStatus": "unaffected", "packageURL": "pkg:npm/h3", "versions": [{"version": "2.0.1-rc.17", "status": "affected", "lessThan": "2.0.1-rc.18", "versionType": "semver"}, {"version": "2.0.1-rc.18", "status": "unaffected", "versionType": "semver"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 5.4, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/h3js/h3/security/advisories/GHSA-fp4x-ggrf-wmc6", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-fp4x-ggrf-wmc6)"}, {"name": "VulnCheck Advisory: h3 before 2.0.1-rc.18 Open Redirect via redirectBack()", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-open-redirect-via-redirectback"}], "credits": [{"lang": "en", "value": "offset", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.0.1-rc.17,2.0.1-rc.18)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[2.0.1-rc.18,2.0.1-rc.18]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "h3", "source": "cna", "vendor": "h3js"}, "product": "h3", "vendor": "h3js"}], "created": "2026-09-06T13:30:07.532390+00:00", "updated": "2026-09-06T13:30:07.831279+00:00", "vendors": ["h3js", "h3js$PRODUCT$h3"]}