4.3
MEDIUM CVSS 3.1
CVE-2026-47675
Hono: Cookie helper does not sanitize sameSite and priority, allowing Set-Cookie injection
Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the serialize() function in hono/cookie validates domain and path options against characters that corrupt Set-Cookie header syntax (;, \r, \n), but does not apply the same validation to sameSite and priority. An application that passes user-controlled input into either option may produce a Set-Cookie response header containing attacker-chosen additional attributes. This vulnerability is fixed in 4.12.21.

INFO

Published Date :

May 28, 2026, 5:16 p.m.

Last Modified :

May 28, 2026, 5:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-47675 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 [email protected]
Solution
Update Hono to version 4.12.21 or later to fix cookie header parsing.
  • Update Hono to version 4.12.21 or later.
  • Apply security patches provided by the vendor.
  • Sanitize user input for cookie options.
  • Validate all cookie-related input parameters.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-47675.

URL Resource
https://github.com/honojs/hono/security/advisories/GHSA-3hrh-pfw6-9m5x
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-47675 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-47675 weaknesses.

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-2026-47675 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-47675 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 28, 2026

    Action Type Old Value New Value
    Added Description Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the serialize() function in hono/cookie validates domain and path options against characters that corrupt Set-Cookie header syntax (;, \r, \n), but does not apply the same validation to sameSite and priority. An application that passes user-controlled input into either option may produce a Set-Cookie response header containing attacker-chosen additional attributes. This vulnerability is fixed in 4.12.21.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
    Added CWE CWE-113
    Added CWE CWE-1287
    Added Reference https://github.com/honojs/hono/security/advisories/GHSA-3hrh-pfw6-9m5x
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.