---
id: CVE-2025-71381
title: >-
  Hono before 4.10.2 (fixed in 4.10.3) contains a flaw in its CORS middleware:
  when the origin is not set to "*", the middleware copies the Vary header from
  the incoming request into the response
summary: >-
  Hono before 4.10.2 (fixed in 4.10.3) contains a flaw in its CORS middleware:
  when the origin is not set to "*", the middleware copies the Vary header from
  the incoming request into the response. Because Vary is a response header that
  sho…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-113
  - CWE-444
vendor: hono
product: hono
affected:
  - hono < 4.10.3
patched:
  - hono 4.10.3
published: '2026-06-30'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T21:10:00.227'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-71381'
references:
  - url: 'https://github.com/honojs/hono/security/advisories/GHSA-q7jf-gf43-6x6p'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/hono-vary-header-injection-in-cors-middleware
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/honojs/hono/commit/d9b8b4b73b4f997994f2764013207365fe711282
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-71381'
  - url: 'https://github.com/advisories/GHSA-q7jf-gf43-6x6p'
tags:
  - nvd
  - ghsa
  - npm
  - cve.org
  - score-dispute
epss: 0.00292
epssPercentile: 0.21647
aliases:
  - GHSA-q7jf-gf43-6x6p
ecosystem: npm
scores:
  nvd: 6.5
  ghsa: 4.2
  cna: 6.5
ingestedAt: '2026-10-02T22:33:09.857Z'
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-07-01T13:19:11.943471Z'
---

## Overview

Hono before 4.10.2 (fixed in 4.10.3) contains a flaw in its CORS middleware: when the origin is not set to "*", the middleware copies the Vary header from the incoming request into the response. Because Vary is a response header that should be managed by the server, an attacker can supply arbitrary Vary values that are reflected into the response, potentially causing cache key pollution and inconsistent CORS enforcement in environments that rely on shared caches or proxies.

## Remediation

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

## Package advisory (CVE-2025-71381)

Affected packages:

- `hono < 4.10.3`

Patched in:

- `hono 4.10.3`

Source: https://github.com/advisories/GHSA-q7jf-gf43-6x6p