CVE-2026-59895Published

Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility

Exact source revision recorded 23 Oct 2026 15:48:27 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-59895

Published

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.0.0 before 4.12.27, cx() in hono/css composes class names from plain strings but marks the result as already escaped without HTML-escaping the input, allowing untrusted className values used in a JSX class attribute during server-side rendering to break out of the attribute and inject arbitrary markup. This issue is fixed in version 4.12.27.

Source published: 8 Jul 2026 16:09:51 UTC
Source modified: 8 Jul 2026 19:41:04 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N