---
id: GHSA-55cm-p4ww-685g
title: >-
  Duplicate Advisory: Hono missing validation of cookie name on write path in
  setCookie()
summary: >-
  Duplicate Advisory: Hono missing validation of cookie name on write path in
  setCookie()
severity: medium
cvss: 5.3
cwe:
  - CWE-20
  - CWE-113
vendor: hono
product: hono
ecosystem: npm
affected:
  - hono < 4.12.12
patched:
  - hono 4.12.12
published: '2026-06-23'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T18:24:43Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-55cm-p4ww-685g'
references:
  - url: 'https://github.com/honojs/hono/security/advisories/GHSA-26pp-8wgv-hjvm'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56762'
  - url: >-
      https://www.vulncheck.com/advisories/hono-missing-cookie-name-validation-in-setcookie
  - url: 'https://github.com/advisories/GHSA-55cm-p4ww-685g'
tags:
  - ghsa
  - npm
ingestedAt: '2026-09-24T18:49:36.714Z'
---

## Overview

### Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-26pp-8wgv-hjvm. This link is maintained to preserve external references.

### Original Description
Hono before 4.12.12 does not validate cookie names on the write path in the setCookie(), serialize(), and serializeSigned() functions, allowing invalid characters such as control characters (e.g. \r or \n) when an application passes a user-controlled cookie name. This can produce malformed Set-Cookie header values. In modern runtimes such as Node.js and Cloudflare Workers, such invalid header values are rejected and cause a runtime error before the response is sent, so header injection or response splitting could not be reproduced; the issue primarily affects correctness and robustness, resulting in runtime errors (availability) rather than confirmed header injection.

## Affected packages

- `hono < 4.12.12`

## Remediation

Upgrade to a patched release:

- `hono 4.12.12`