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CVE-2026-59895

CVE-2026-59895 · Hono: Server-Side XSS via JSX Escaping Bypass in cx() Utility

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 6.1 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • hono

    Versions
    • >= 4.0.0, < 4.12.27: Affected

    No fix published

  • hono npm

    Affected ranges
    • SEMVER: ≥ 4.0.0, < 4.12.27

    Update to 4.12.27

Original sources

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