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

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 an...

CVE-2026-47675

Summary: Hono prior to 4.12.21 has a vulnerability in the serialize() function of hono/cookie where domain and path options are validated to prevent Set-Cookie header corruption, but sameSite and priority are not validated. This can allow user-controlled input to inject attacker-chosen attributes...

Tornado has incomplete validation of cookie attributes

Values passed to the domain, path, and samesite arguments of RequestHandler.setcookie were not completely validated in versions of Tornado prior to 6.5.5. In particular, semicolons would be allowed, which could be used to inject attacker-controlled values for other cookie attributes...