6.9
MEDIUM CVSS 4.0
CVE-2025-71381
Hono - Vary Header Injection in CORS Middleware
Description

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.

INFO

Published Date :

June 30, 2026, 10:08 p.m.

Last Modified :

June 30, 2026, 10:08 p.m.

Remotely Exploit :

Yes !

Source :

VulnCheck
Affected Products

The following products are affected by CVE-2025-71381 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
Solution
Update Hono to version 4.10.3 or later to fix the CORS middleware flaw.
  • Update Hono to version 4.10.3 or later.
  • Ensure CORS middleware configuration is secure.
  • Remove or restrict custom Vary header handling.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-71381 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.