CVE-2026-54286
Full vulnerability record from the local CVENow database.
Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on Windows hosts, an encoded backslash (%5C) in the request path decodes to \, which the Windows path resolver treats as a separator. serve-static then resolves a single URL segment such as admin\secret.txt into a nested file under the root and serves it, letting an attacker read static files meant to be protected behind prefix-mounted middleware. This vulnerability is fixed in 4.12.25.
Severity
MEDIUM
CVSS score
5.9
(v3.1)
Vulnerability status
Deferred
Source identifier
Published
2026-06-22 18:16:47.213000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
"id": "CVE-2026-54286",
"sourceIdentifier": "[email protected]",
"published": "2026-06-22T18:16:47.213",
"lastModified": "2026-10-25T23:10:00.167",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on Windows hosts, an encoded backslash (%5C) in the request path decodes to \\, which the Windows path resolver treats as a separator. serve-static then resolves a single URL segment such as admin\\secret.txt into a nested file under the root and serves it, letting an attacker read static files meant to be protected behind prefix-mounted middleware. This vulnerability is fixed in 4.12.25."
},
{
"lang": "es",
"value": "Hono es un framework de aplicación web que proporciona soporte para cualquier entorno de ejecución de JavaScript. Antes de la versión 4.12.25, en hosts de Windows, una barra invertida codificada (%5C) en la ruta de la solicitud se decodifica a \\, que el resolvedor de rutas de Windows trata como un separador. serve-static entonces resuelve un único segmento de URL como admin\\secret.txt en un archivo anidado bajo la raíz y lo sirve, permitiendo a un atacante leer archivos estáticos destinados a ser protegidos detrás de un middleware montado con prefijo. Esta vulnerabilidad está corregida en la versión 4.12.25."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "honojs",
"product": "hono",
"versions": [
{
"version": "< 4.12.25",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
"baseScore": 5.9,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.2,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-06-23T14:07:25.570505Z",
"id": "CVE-2026-54286",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-22"
}
]
}
],
"references": [
{
"url": "https://github.com/honojs/hono/security/advisories/GHSA-wwfh-h76j-fc44",
"source": "[email protected]"
}
]
}