{"id":"CVE-2026-69204","summary":"Http4s: Ember accepts Transfer-Encoding combined with Content-Length (CL.TE request smuggling)","details":"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 that forwards both headers and frames by Content-Length, an unauthenticated attacker can smuggle a second request, bypass intermediary access controls, poison caches, or cause a victim request to be joined to an attacker-controlled prefix. The shared response parser can also desynchronize an ember-client connection when a malicious or compromised upstream sends both headers. This issue is fixed in versions 0.23.35 and 1.0.0-M47.","aliases":["GHSA-8h4c-x2wg-6xp8"],"modified":"2026-09-18T03:30:24.725198766Z","published":"2026-09-15T18:43:14.850Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69204.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-444"]},"references":[{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v0.23.35"},{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69204.json"},{"type":"ADVISORY","url":"https://github.com/http4s/http4s/security/advisories/GHSA-8h4c-x2wg-6xp8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-69204"},{"type":"FIX","url":"https://github.com/http4s/http4s/commit/9feaf8677951a52af906ae9664ff6f0543d9d810"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/http4s/http4s","events":[{"introduced":"0"},{"introduced":"756ce63aee681c5b632bbeafe0b8fde2f3d237f4"},{"fixed":"a83f5f4f7e14c5b4d4a91dd71b105cbbbb391298"},{"fixed":"6083780a3009bd7b26033b0ceb3d32c658b0377e"},{"fixed":"9feaf8677951a52af906ae9664ff6f0543d9d810"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.23.35"},{"introduced":"1.0.0-M1"},{"fixed":"1.0.0-M47"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v1.0.0-M46","v0.23.34","v0.23.33","v1.0.0-M45","v0.23.32","v0.23.31","v1.0.0-M44","v0.23.30","v1.0.0-M43","v1.0.0-M42","v0.23.29","v0.23.28","v0.23.27","v1.0.0-M41","v0.23.26","v0.23.25","v0.23.24","v0.23.23","v1.0.0-M40","v0.23.22","v0.23.20","v0.23.19","v0.23.19-RC2","v0.23.19-RC1","v1.0.0-M39","v0.23.18","v1.0.0-M37","v0.23.16","v1.0.0-M36","v0.23.15","v1.0.0-M35","v0.23.14","v1.0.0-M34","v0.23.13","v1.0.0-M33","v0.23.12","v1.0.0-M32","v0.23.11","v1.0.0-M31","v0.23.10","v0.23.9","v0.23.8","v1.0.0-M30","v0.23.7","v1.0.0-M29","v0.23.6","v0.23.5","v1.0.0-M28","v0.23.3","v1.0.0-M26","v0.23.2","v1.0.0-M24","v0.23.1","v0.23.0","v1.0.0-M22","v0.23.0-M1","v1.0.0-M21","v1.0.0-M20","v1.0.0-M19","v1.0.0-M17","v1.0.0-M16","v1.0.0-M15","v1.0.0-M13","v1.0.0-M12","v1.0.0-M11","v1.0.0-M10","v1.0.0-M9","v1.0.0-M8","v1.0.0-M7","v1.0.0-M6","v1.0.0-M5","v1.0.0-M4","v1.0.0-M3","v1.0.0-M2","v1.0.0-M1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-69204.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N"}]}