---
id: CVE-2026-69211
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,
  ResponseCookie.render writes attacker-influenced name, content, domain, path,
  and extension values without neutralizing semicolons or control characters. An
  a…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-113
  - CWE-1286
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-2026-69211'
references:
  - url: >-
      https://github.com/http4s/http4s/commit/5c8e69ac0f4a2fe03c3481dccd74101cd2e2a890
    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-7qh7-rghh-698h'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T13:55:53.661721Z'
ingestedAt: '2026-09-15T19:42:58.804Z'
epss: 0.00216
epssPercentile: 0.1234
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.