{"cve":"CVE-2025-59822","nvd":{"published":"2025-09-23T19:15:42.303","modified":"2026-10-19T16:10:00.260","status":"Analyzed","description":"Http4s is a Scala interface for HTTP services. In versions from 1.0.0-M1 to before 1.0.0-M45 and before 0.23.31, http4s is vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section. This vulnerability could enable attackers to bypass front-end servers security controls, launch targeted attacks against active users, and poison web caches. A pre-requisite for exploitation involves the web application being deployed behind a reverse-proxy that forwards trailer headers. This issue has been patched in versions 1.0.0-M45 and 0.23.31.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-444"],"references":["https://github.com/http4s/http4s/commit/dd518f7c967e5165813b8d4a48a82b8fab852d41","https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr","https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr"],"products":["typelevel:http4s"],"source":"nvd","synced_at":"2026-10-19T22:10:08.713834912+00:00"},"epss":{"cve":"CVE-2025-59822","score":0.00374,"percentile":0.31064,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wcwh-7gfw-5wrr","url":"https://osv.dev/vulnerability/GHSA-wcwh-7gfw-5wrr","summary":"Http4s vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section","modified":"2025-10-13T15:45:42.428092Z","packages":[{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.12","purl":"pkg:maven/org.http4s/http4s-ember-core_2.12","ranges":["<0.23.31"],"fixed":["0.23.31"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","purl":"pkg:maven/org.http4s/http4s-ember-core_2.13","ranges":["<0.23.31"],"fixed":["0.23.31"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","purl":"pkg:maven/org.http4s/http4s-ember-core_3","ranges":["<0.23.31"],"fixed":["0.23.31"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_2.13","purl":"pkg:maven/org.http4s/http4s-ember-core_2.13","ranges":[">=1.0.0-M1 <1.0.0-M45"],"fixed":["1.0.0-M45"]},{"ecosystem":"Maven","name":"org.http4s:http4s-ember-core_3","purl":"pkg:maven/org.http4s/http4s-ember-core_3","ranges":[">=1.0.0-M1 <1.0.0-M45"],"fixed":["1.0.0-M45"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}