Improper Encoding or Escaping of Output Affecting hono package, versions >=4.3.0 <4.12.18
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Improper Encoding or Escaping of Output vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-JS-HONO-16624528
- published10 May 2026
- disclosed9 May 2026
- creditGayang2902
Introduced: 9 May 2026
NewCVE-2026-44458 (opens in a new tab)How to fix?
Upgrade hono to version 4.12.18 or higher.
Overview
hono is an Ultrafast web framework for the Edges
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output the styleObjectForEach and jsxAttr style serialization paths in the JSX runtime. An attacker can inject arbitrary CSS declarations by supplying crafted style object values or property names containing declaration separators such as ;, comments, braces, or other CSS syntax, causing the generated style attribute to include attacker-controlled rules. When application code renders untrusted style objects, the injected CSS can override the page's layout and presentation, hide or reposition content, and load attacker-controlled resources in the victim’s browser, but does not enable JavaScript execution or HTML attribute breakout.