{"id":"CVE-2026-69204","title":"Http4s is a Scala interface for HTTP services","summary":"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 r…","severity":"critical","cvss":9.2,"cvssVector":"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","cwe":["CWE-444"],"vendor":"http4s","product":"http4s","affected":["http4s < 0.23.35","http4s >= 1.0.0-M1, < 1.0.0-M47"],"patched":["org.http4s:http4s-ember-core_2.12 0.23.35","org.http4s:http4s-ember-core_2.13 0.23.35","org.http4s:http4s-ember-core_3 0.23.35","org.http4s:http4s-ember-core_2.13 1.0.0-M47","org.http4s:http4s-ember-core_3 1.0.0-M47"],"published":"2026-09-15","updated":"2026-09-16","sourceUpdated":"2026-09-16T20:39:16.610","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-69204","references":[{"url":"https://github.com/http4s/http4s/commit/9feaf8677951a52af906ae9664ff6f0543d9d810","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/releases/tag/v0.23.35","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47","label":"security-advisories@github.com"},{"url":"https://github.com/http4s/http4s/security/advisories/GHSA-8h4c-x2wg-6xp8","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-8h4c-x2wg-6xp8"}],"tags":["nvd","cve.org","ghsa","maven"],"aliases":["GHSA-8h4c-x2wg-6xp8"],"ecosystem":"maven","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-15T19:00:36.832324Z"},"cvssSource":"cna","ingestedAt":"2026-09-15T19:42:58.803Z","epss":0.00331,"epssPercentile":0.26456,"slug":"CVE-2026-69204","body":"## Overview\n\nHttp4s 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-69204)\n\nAffected packages:\n\n- `org.http4s:http4s-ember-core_2.12 <= 0.23.34`\n- `org.http4s:http4s-ember-core_2.13 <= 0.23.34`\n- `org.http4s:http4s-ember-core_3 <= 0.23.34`\n- `org.http4s:http4s-ember-core_2.13 >= 1.0.0-M1, <= 1.0.0-M46`\n- `org.http4s:http4s-ember-core_3 >= 1.0.0-M1, <= 1.0.0-M46`\n\nPatched in:\n\n- `org.http4s:http4s-ember-core_2.12 0.23.35`\n- `org.http4s:http4s-ember-core_2.13 0.23.35`\n- `org.http4s:http4s-ember-core_3 0.23.35`\n- `org.http4s:http4s-ember-core_2.13 1.0.0-M47`\n- `org.http4s:http4s-ember-core_3 1.0.0-M47`\n\nSource: https://github.com/advisories/GHSA-8h4c-x2wg-6xp8","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":50.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}