CVE-2026-126358

Hono: RegExpRouter skips wildcard middleware for some route sets and for paths with an encoded line terminator

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.1.4 until 4.13.16, RegExpRouter can omit wildcard middleware in three version-specific cases: since 4.13.0, middleware using the explicit default parameter pattern in /api/:tenant{[^/]+}/admin/* is not applied to a route written as /api/:tenant/admin/:id; since 4.1.4, middleware on /admin/* is not applied to a route registered as /admin* for paths under /admin/; and since 4.4.0, a request path containing an encoded line terminator can reach the not-found handler without wildcard middleware. The default SmartRouter selects RegExpRouter for most applications, and the router's registration-time coverage calculation treated the first two matching pattern pairs as different while its compiled wildcard did not match line terminators in the third case. An unauthenticated client can reach a route handler or the not-found handler without authentication or authorization middleware registered on the wildcard path. TrieRouter, LinearRouter, and PatternRouter apply the middleware in the three described cases. This issue is fixed in version 4.13.16.