Improper handling of JSX attribute names in hono/jsx allows malformed attribute keys to corrupt the generated HTML output.
When untrusted input is used as attribute keys during server-side rendering, specially crafted keys can break out of attribute or tag boundaries and inject unintended HTML.
When rendering JSX elements to HTML strings, attribute values are escaped, but attribute names (keys) were previously inserted into the output without validation.
If an attribute name contains characters such as ", >, or whitespace, it can alter the structure of the generated HTML.
For example, malformed attribute names can:
This issue arises when untrusted input (such as query parameters or form data) is used as JSX attribute keys during server-side rendering.
An attacker who can control attribute keys used in JSX rendering may inject unintended attributes or HTML elements into the generated output.
This may lead to:
This issue affects applications that pass untrusted input as JSX attribute keys during server-side rendering.
{
"github_reviewed": true,
"severity": "MODERATE",
"nvd_published_at": null,
"cwe_ids": [
"CWE-79"
],
"github_reviewed_at": "2026-04-16T01:02:24Z"
}