CVE-2026-47675
Medium
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.
SeverityMedium
CVSS4.3
Exploit probability—
Product
Hono
PublishedMay 28, 2026
First seenMay 28, 2026
Weakness typeCWE-113CWE-113CWE-1287CWE-1287
How to fix
Update
- hono hono4.12.21 or later
- hono4.12.21 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| hono hono | v < 4.12.21 | 4.12.21 |
| hononpm | v < 4.12.21 | 4.12.21 |
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