Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when < ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the <Style /> element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after < in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-79"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126359.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "3.12.0"
},
{
"fixed": "4.13.16"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v4.13.16",
"range": [
{
"fixed": "c91b60a251186fb024557c6d55a11d8e388f179c"
}
],
"source": "REFERENCES_TAG"
}
]
}