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 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.
Hono: app.mount() strips mount prefix using undecoded path, causing incorrect routing for percent-encoded paths
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed against the percent-decoded path. This inconsistency causes the prefix to be stripped at the wrong position when the path contains percent-encoded multi-byte characters, resulting in the mounted sub-application receiving an incorrect path. This vulnerability is fixed in 4.12.21.
Hono: Improper validation of NumericDate claims (exp, nbf, iat) in JWT verify()
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, improper validation of the JWT NumericDate claims exp, nbf, and iat in hono/utils/jwt allows tokens with non-spec-compliant claim values to silently bypass time-based checks. This issue is not exploitable by an anonymous attacker; it only manifests when a malformed claim value reaches verify() — typically when the application itself issues such tokens, or when the signing key is otherwise under attacker control. This vulnerability is fixed in 4.12.18.
Hono: CSS Declaration Injection via Style Object Values in JSX SSR
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, the JSX renderer escapes style attribute object values for HTML but not for CSS. Untrusted input in a style object value or property name can therefore inject additional CSS declarations into the rendered style attribute. The impact is limited to CSS and does not allow JavaScript execution or HTML attribute breakout. This vulnerability is fixed in 4.12.18.
Hono: Cache Middleware ignores Vary: Authorization / Vary: Cookie leading to cross-user cache leakage
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, Cache Middleware does not skip caching for responses that declare per-user variance via Vary: Authorization or Vary: Cookie. As a result, a response cached for one authenticated user may be served to subsequent requests from different users. This vulnerability is fixed in 4.12.18.
Hono: bodyLimit() can be bypassed for chunked / unknown-length requests
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.16, bodyLimit() does not reliably enforce maxSize for requests without a usable Content-Length (e.g. Transfer-Encoding: chunked). Oversized requests can reach handlers and return 200 instead of 413. This vulnerability is fixed in 4.12.16.
Hono: Unvalidated JSX Tag Names in hono/jsx May Allow HTML Injection
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.16, Improper handling of JSX element tag names in hono/jsx allowed unvalidated tag names to be directly inserted into the generated HTML output. When untrusted input is used as a tag name via the programmatic jsx() or createElement() APIs during server-side rendering, specially crafted values may break out of the intended element context and inject unintended HTML. This vulnerability is fixed in 4.12.16.