{"id":"DEBIAN-CVE-2026-42581","details":"Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.","modified":"2026-09-19T22:47:41.437438153Z","published":"2026-05-13T19:17:23.627Z","upstream":["CVE-2026-42581"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-42581"}],"affected":[{"package":{"name":"netty","ecosystem":"Debian:12","purl":"pkg:deb/debian/netty?arch=source&distro=bookworm"},"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","1:4.1.48-15","1:4.1.48-16","1:4.1.48-7","1:4.1.48-7+deb12u1","1:4.1.48-7+deb12u2","1:4.1.48-8","1:4.1.48-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42581.json"}},{"package":{"name":"netty","ecosystem":"Debian:13","purl":"pkg:deb/debian/netty?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.48-10","1:4.1.48-10+deb13u1","1:4.1.48-11","1:4.1.48-12","1:4.1.48-13","1:4.1.48-14","1:4.1.48-15","1:4.1.48-16"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42581.json"}},{"package":{"name":"netty","ecosystem":"Debian:14","purl":"pkg:deb/debian/netty?arch=source&distro=forky"},"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","1:4.1.48-15","1:4.1.48-16"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42581.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:H/I:H/A:H"}]}