{"id":"CVE-2026-69217","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’s HTTP/1.1 parser accepts differing duplicate Content-Length headers and uses the last value instead of rejecting the message. When an Ember server is b…","severity":"high","cvss":8.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","cwe":["CWE-444"],"vendor":"http4s","product":"http4s","affected":["http4s < 0.23.35","http4s >= 1.0.0-M1, < 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-2026-69217","references":[{"url":"https://github.com/http4s/http4s/commit/24e8d34e3ea89f8f23e0053ec9944f6467e8086d","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-p83c-4wj9-p6w9","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-16T13:52:29.524145Z"},"ingestedAt":"2026-09-15T19:42:58.833Z","epss":0.00499,"epssPercentile":0.41616,"slug":"CVE-2026-69217","body":"## Overview\n\nHttp4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HTTP/1.1 parser accepts differing duplicate Content-Length headers and uses the last value instead of rejecting the message. When an Ember server is behind a keep-alive intermediary that selects a different occurrence, an unauthenticated attacker can create CL.CL request smuggling that bypasses front-end controls, captures a later user’s headers, or poisons a cache. The shared client parser can also misframe responses from a malicious or compromised upstream when the client acts as a proxy for multiple downstream consumers. 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.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}