{"id":"UBUNTU-CVE-2026-100659","details":"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.","modified":"2026-09-29T23:41:44.808550412Z","published":"2026-09-29T00:00:00Z","upstream":["CVE-2026-100659"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-100659"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-100659"},{"type":"REPORT","url":"https://github.com/netty/netty/security/advisories/GHSA-q9pg-8h3j-8hvm"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/netty-4.2.0-through-4.2.18-http-3-request-routing-bypass"}],"affected":[{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:3.2.6.Final-2","1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1","1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:3.2.6.Final-2","1:4.0.32-1","1:4.0.33-1","1:4.0.34-1","1:4.0.34-1ubuntu0.1~esm1","1:4.0.34-1ubuntu0.1~esm2","1:4.0.34-1ubuntu0.1~esm3","1:4.0.34-1ubuntu0.1~esm4","1:4.0.34-1ubuntu0.1~esm5"],"ecosystem_specific":{"binaries":[{"binary_version":"1:4.0.34-1ubuntu0.1~esm5","binary_name":"libnetty-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.7-4","1:4.1.7-4ubuntu0.1~esm1","1:4.1.7-4ubuntu0.1","1:4.1.7-4ubuntu0.1+esm1","1:4.1.7-4ubuntu0.1+esm2","1:4.1.7-4ubuntu0.1+esm3","1:4.1.7-4ubuntu0.1+esm4","1:4.1.7-4ubuntu0.1+esm5","1:4.1.7-4ubuntu0.1+esm6","1:4.1.7-4ubuntu0.1+esm7"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:4.1.7-4ubuntu0.1+esm7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.33-1","1:4.1.33-2","1:4.1.33-3","1:4.1.45-1","1:4.1.45-1ubuntu0.1~esm1","1:4.1.45-1ubuntu0.1~esm2","1:4.1.45-1ubuntu0.1~esm3","1:4.1.45-1ubuntu0.1~esm4","1:4.1.45-1ubuntu0.1~esm6","1:4.1.45-1ubuntu0.1~esm7"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:4.1.45-1ubuntu0.1~esm7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.48-4","1:4.1.48-4+deb11u1build0.22.04.1","1:4.1.48-4+deb11u2build0.22.04.1","1:4.1.48-4+deb11u2ubuntu0.1~esm1","1:4.1.48-4+deb11u2ubuntu0.1~esm2","1:4.1.48-4+deb11u2ubuntu0.1","1:4.1.48-4+deb11u2ubuntu0.1+esm1","1:4.1.48-4+deb11u2ubuntu0.1+esm3","1:4.1.48-4+deb11u2ubuntu0.2","1:4.1.48-4+deb11u2ubuntu0.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:4.1.48-4+deb11u2ubuntu0.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.48-7","1:4.1.48-8","1:4.1.48-9","1:4.1.48-9ubuntu0.1~esm1","1:4.1.48-9ubuntu0.1~esm2","1:4.1.48-9ubuntu0.1","1:4.1.48-9ubuntu0.1+esm1","1:4.1.48-9ubuntu0.1+esm3","1:4.1.48-9ubuntu0.2","1:4.1.48-9ubuntu0.2+esm1","1:4.1.48-9ubuntu0.2+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:4.1.48-9ubuntu0.2+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100659.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.48-10","1:4.1.48-11","1:4.1.48-12","1:4.1.48-13","1:4.1.48-14","1:4.1.48-16","1:4.1.48-16ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-buffer-java","binary_version":"1:4.1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