CVE-2026-69211

Medium

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.

SeverityMedium
CVSS4.8
Exploit probability—
ProductHttp4s
PublishedSep 15, 2026
First seenSep 15, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
http4s http4s< 0.23.35, >= 1.0.0-M1, < 1.0.0-M47—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.