CVE-2026-69211
MEDIUM
NVD
CVSS Score
4.8
Severity
MEDIUM
Published
Sep 15, 2026
Vendor
unknown
Description
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, ResponseCookie.render writes attacker-influenced name, content, domain, path, and extension values without neutralizing semicolons or control characters. An application that constructs a ResponseCookie from unvalidated input can therefore emit injected cookie attributes such as Domain, Path, or SameSite, widening cookie scope or weakening protections, and control characters may enable header splitting on permissive backends. The patch strips control characters from all five fields and strips semicolons from name, content, domain, and path while retaining the extension delimiter behavior. This issue is fixed in versions 0.23.35 and 1.0.0-M47.