CVE-2026-47675 MEDIUM

CVE-2026-47675: Hono: Cookie helper does not sanitize sameSite and priority, allowing Set-Cookie injection

Vendor Honojs
Product hono
Weakness CWE-113 · HTTP response splitting
Published May 28, 2026
Last update May 28, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 28, 2026 CVE published
May 28, 2026 Record updated