Hono is a Web application framework that provides support for any JavaScript runtime. Hono CSRF middleware can be bypassed using crafted Content-Type header. MIME types are case insensitive, but isRequestedByFormElementRe only matches lower-case. As a result, attacker can bypass csrf middleware using upper-case form-like MIME type. This vulnerability is fixed in 4.5.8.
https://github.com/honojs/hono/security/advisories/GHSA-rpfr-3m35-5vx5
https://github.com/honojs/hono/commit/41ce840379516410dee60c783142e05bb5a22449