---
id: CVE-2026-71849
title: >-
  Hono is a Web application framework that provides support for any JavaScript
  runtime
summary: >-
  Hono is a Web application framework that provides support for any JavaScript
  runtime. From 4.7.0 to 4.12.33, the Proxy Helper proxy() function in
  hono/proxy does not remove response headers named by the origin's Connection
  header. Per RF…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-200
vendor: hono
product: hono
affected:
  - 'hono >= 4.7.0, < 4.12.34'
patched:
  - hono 4.12.34
published: '2026-08-07'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:02:22.660'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71849'
references:
  - url: >-
      https://github.com/honojs/hono/commit/720b566290793d4358bf39843adcb7cf4da4548f
    label: security-advisories@github.com
  - url: 'https://github.com/honojs/hono/releases/tag/v4.12.34'
    label: security-advisories@github.com
  - url: 'https://github.com/honojs/hono/security/advisories/GHSA-79qm-7rj5-m7r9'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-79qm-7rj5-m7r9'
tags:
  - nvd
  - ghsa
  - npm
epss: 0.00236
epssPercentile: 0.14813
aliases:
  - GHSA-79qm-7rj5-m7r9
ecosystem: npm
ingestedAt: '2026-08-07T19:16:20.248Z'
---

## Overview

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.7.0 to 4.12.33, the Proxy Helper proxy() function in hono/proxy does not remove response headers named by the origin's Connection header. Per RFC 9110 Section 7.6.1, an intermediary must remove the header fields listed in a message's Connection header field before forwarding the message, in addition to the well known hop by hop headers, but the proxy() function only removed the well known hop by hop headers, including Connection itself, from origin responses. A client may therefore receive response headers that the origin intended only for its immediate peer, disclosing connection scoped or internal metadata contained in such headers, when an application proxies responses from an origin that declares additional, non standard headers as hop by hop via the Connection response header. This issue is fixed in version 4.12.34.

## Remediation

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

## Package advisory (CVE-2026-71849)

Affected packages:

- `hono >= 4.7.0, < 4.12.34`

Patched in:

- `hono 4.12.34`

Source: https://github.com/advisories/GHSA-79qm-7rj5-m7r9