CVE-2026-69204 Http4s: Ember accepts Transfer-Encoding combined with Content-Length (CL.TE request smuggling)

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember HTTP/1.1 does not reject messages containing both Transfer-Encoding and Content-Length, so an intermediary and Ember can select different body framing rules. When ember-server is behind a keep-alive intermediary...

EUVD-2026-69235

httpd function checkheader/3 rejects duplicate Content-Length per CVE-2026-23941 but never checks for the TE+CL co-presence that RFC 9112 §6.3 identifies as a probable smuggling attempt. handlebody/3 frames by chunked and silently discards Content-Length. A CL-preferring front-end paired with...