CVE-2026-39410 Hono has a non-breaking space prefix bypass in cookie name handling in getCookie()

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a discrepancy between browser cookie parsing and parse handling allows cookie prefix protections to be bypassed. Cookie names that are treated as distinct by the browser may be normalized to th...

Hono: Non-breaking space prefix bypass in cookie name handling in getCookie()

Summary A discrepancy between browser cookie parsing and parse handling allows cookie prefix protections to be bypassed. Cookie names that are treated as distinct by the browser may be normalized to the same key by parse, allowing attacker-controlled cookies to override legitimate ones. Details...