{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-100659", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-26T02:33:59.039Z", "datePublished": "2026-09-26T13:23:26.859Z", "dateUpdated": "2026-09-26T13:23:26.859Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-26T13:23:26.859Z"}, "datePublic": "2026-09-10T00:00:00.000Z", "title": "Netty 4.2.0 through 4.2.18 HTTP/3 Request Routing Bypass", "descriptions": [{"lang": "en", "value": "Netty's HTTP/3 codec (io.netty:netty-codec-http3) in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single HEADERS frame containing both fields with differing, attacker-controlled values; the request is accepted and delivered to the application with two conflicting authorities, allowing routing, virtual-host, and access-control decisions to be bypassed when different components in the request path consult different fields. This issue is fixed in 4.2.18.Final."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')", "cweId": "CWE-444", "type": "CWE"}]}], "affected": [{"vendor": "netty", "product": "netty", "defaultStatus": "unaffected", "packageURL": "pkg:maven/io.netty/netty-codec-http3", "versions": [{"version": "4.2.0.Final", "status": "affected", "versionType": "semver", "lessThan": "4.2.18.Final"}, {"version": "4.2.18.Final", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2.0.final", "versionEndExcluding": "4.2.18.final"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/netty/netty/security/advisories/GHSA-q9pg-8h3j-8hvm", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-q9pg-8h3j-8hvm)"}, {"name": "VulnCheck Advisory: Netty 4.2.0 through 4.2.18 HTTP/3 Request Routing Bypass", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/netty-4.2.0-through-4.2.18-http-3-request-routing-bypass"}], "credits": [{"lang": "en", "value": "violetagg", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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