{"id":"UBUNTU-CVE-2026-93491","details":"A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.","modified":"2026-09-21T21:41:00.372684819Z","published":"2026-09-21T00:00:00Z","upstream":["CVE-2026-93491"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-93491"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-93491"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2536891"},{"type":"REPORT","url":"https://github.com/netty/netty/security/advisories/GHSA-pvjx-v7vp-62vq"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2026-93491"},{"type":"REPORT","url":"https://github.com/netty/netty/releases/tag/netty-4.1.138.Final"},{"type":"REPORT","url":"https://github.com/netty/netty/releases/tag/netty-4.2.18.Final"}],"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_version":"1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1","binary_name":"libnetty-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93491.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_name":"libnetty-java","binary_version":"1:4.0.34-1ubuntu0.1~esm5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93491.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-2026-93491.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-2026-93491.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_version":"1:4.1.48-4+deb11u2ubuntu0.2+esm1","binary_name":"libnetty-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93491.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-2026-93491.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_version":"1:4.1.48-16ubuntu0.1~esm2","binary_name":"libnetty-buffer-java"},{"binary_name":"libnetty-common-java","binary_version":"1:4.1.48-16ubuntu0.1~esm2"},{"binary_name":"libnetty-java","binary_version":"1:4.1.48-16ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93491.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}