CVE-2026-46395
Full vulnerability record from the local CVENow database.
Description
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, the `hmacBase64()` function in the HAXcms Node.js backend contains two critical cryptographic implementation errors that together allow any unauthenticated attacker to extract the system’s private signing key and forge arbitrary admin-level JSON Web Tokens (JWTs) allowing them to get full admin access with a single HTTP request. First, the function passes the literal string "0" as the HMAC signing key instead of the key parameter, making every HAXcms instance compute identical HMACs for the same input. Then, after computing the HMAC, the function concatenates the real key parameter which is "this.privateKey + this.salt", the system’s master signing secret is directly onto the output. The combined buffer is base64-encoded and returned as the token. Every base64url token produced has the same structure: 32 bytes HMAC keyed with "0" and N bytes of `privateKey+salt`. An attacker base64-decodes any token, discards the first 32 bytes, and reads the private key directly. The `/system/api/connectionSettings` endpoint is unauthenticated and returns multiple tokens generated by this function. A single GET request to this endpoint exposes the private key. The PHP backend implements this function correctly with the actual key and returns only the hash. The PHP version produces 44-character tokens whereas the broken Node.js version produces 139+ character tokens. Version 26.0.0 fixes the issue.
View original CVE JSON
{
"id": "CVE-2026-46395",
"sourceIdentifier": "[email protected]",
"published": "2026-06-05T19:16:33.593",
"lastModified": "2026-10-26T11:10:00.157",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, the `hmacBase64()` function in the HAXcms Node.js backend contains two critical cryptographic implementation errors that together allow any unauthenticated attacker to extract the system’s private signing key and forge arbitrary admin-level JSON Web Tokens (JWTs) allowing them to get full admin access with a single HTTP request. First, the function passes the literal string \"0\" as the HMAC signing key instead of the key parameter, making every HAXcms instance compute identical HMACs for the same input. Then, after computing the HMAC, the function concatenates the real key parameter which is \"this.privateKey + this.salt\", the system’s master signing secret is directly onto the output. The combined buffer is base64-encoded and returned as the token. Every base64url token produced has the same structure: 32 bytes HMAC keyed with \"0\" and N bytes of `privateKey+salt`. An attacker base64-decodes any token, discards the first 32 bytes, and reads the private key directly. The `/system/api/connectionSettings` endpoint is unauthenticated and returns multiple tokens generated by this function. A single GET request to this endpoint exposes the private key. The PHP backend implements this function correctly with the actual key and returns only the hash. The PHP version produces 44-character tokens whereas the broken Node.js version produces 139+ character tokens. Version 26.0.0 fixes the issue."
},
{
"lang": "es",
"value": "HAX CMS ayuda a gestionar el universo de micrositios con backends de PHP o NodeJs. Antes de la versión 26.0.0, la función ’hmacBase64()’ en el backend de Node.js de HAXcms contiene dos errores críticos de implementación criptográfica que, en conjunto, permiten a cualquier atacante no autenticado extraer la clave de firma privada del sistema y falsificar JSON Web Tokens (JWTs) arbitrarios de nivel de administrador, lo que les permite obtener acceso de administrador completo con una única solicitud HTTP. Primero, la función pasa la cadena literal ’0’ como clave de firma HMAC en lugar del parámetro de clave, lo que hace que cada instancia de HAXcms calcule HMAC idénticos para la misma entrada. Luego, después de calcular el HMAC, la función concatena el parámetro de clave real, que es ’this.privateKey + this.salt’, el secreto de firma maestro del sistema, directamente a la salida. El búfer combinado se codifica en base64 y se devuelve como el token. Cada token base64url producido tiene la misma estructura: 32 bytes HMAC con clave ’0’ y N bytes de ’privateKey+salt’. Un atacante decodifica en base64 cualquier token, descarta los primeros 32 bytes y lee la clave privada directamente. El endpoint ’/system/API/connectionSettings’ no está autenticado y devuelve múltiples tokens generados por esta función. Una única solicitud GET a este endpoint expone la clave privada. El backend de PHP implementa esta función correctamente con la clave real y devuelve solo el hash. La versión de PHP produce tokens de 44 caracteres, mientras que la versión de Node.js defectuosa produce tokens de más de 139 caracteres. La versión 26.0.0 corrige el problema."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "haxtheweb",
"product": "haxcms-nodejs",
"versions": [
{
"version": "< 26.0.0",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"baseScore": 9.3,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-06-05T19:41:20.331148Z",
"id": "CVE-2026-46395",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-200"
},
{
"lang": "en",
"value": "CWE-321"
},
{
"lang": "en",
"value": "CWE-327"
}
]
}
],
"references": [
{
"url": "https://github.com/haxtheweb/issues/security/advisories/GHSA-6c8g-9hfh-pq5h",
"source": "[email protected]"
},
{
"url": "https://github.com/haxtheweb/issues/security/advisories/GHSA-6c8g-9hfh-pq5h",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}