CVE-2026-61456
Full vulnerability record from the local CVENow database.
Description
The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 fails to sanitize SVG files uploaded through the POST /api/v1/media endpoint. The HandlesMediaUploads::processUploadedFile() method validates only the file extension and never invokes Security::sanitizeSVG(), so an authenticated attacker with the api.media.write permission can upload an SVG containing arbitrary JavaScript. The file is stored unmodified and served with Content-Type: image/svg+xml; when an administrator opens it in a browser (directly or via <object>/<iframe>), the embedded script executes in their session context, enabling cookie theft and session hijacking.
Severity
MEDIUM
CVSS score
5.1
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-07-10 15:16:51.023000
Last modified
2026-10-25 15:10:00.147000
View original CVE JSON
{
"id": "CVE-2026-61456",
"sourceIdentifier": "[email protected]",
"published": "2026-07-10T15:16:51.023",
"lastModified": "2026-10-25T15:10:00.147",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 fails to sanitize SVG files uploaded through the POST /api/v1/media endpoint. The HandlesMediaUploads::processUploadedFile() method validates only the file extension and never invokes Security::sanitizeSVG(), so an authenticated attacker with the api.media.write permission can upload an SVG containing arbitrary JavaScript. The file is stored unmodified and served with Content-Type: image/svg+xml; when an administrator opens it in a browser (directly or via <object>/<iframe>), the embedded script executes in their session context, enabling cookie theft and session hijacking."
},
{
"lang": "es",
"value": "El plugin de API de Grav (getgrav/grav-plugin-api) anterior a la versión 1.0.3 no logra sanear los archivos SVG subidos a través del endpoint POST /api/v1/media. El método HandlesMediaUploads::processUploadedFile() valida solo la extensión del archivo y nunca invoca Security::sanitizeSVG(), por lo que un atacante autenticado con el permiso api.media.write puede subir un SVG que contenga JavaScript arbitrario. El archivo se almacena sin modificar y se sirve con Content-Type: image/svg+xml; cuando un administrador lo abre en un navegador (directamente o a través de [object_tag]/[iframe_tag]), el script incrustado se ejecuta en el contexto de su sesión, lo que permite el robo de cookies y el secuestro de sesión."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "getgrav",
"product": "grav",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"lessThan": "1.0.3",
"versionType": "semver",
"status": "affected"
},
{
"version": "1.0.3",
"versionType": "semver",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/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": 5.1,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "LOW",
"userInteraction": "PASSIVE",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "LOW",
"vulnAvailabilityImpact": "NONE",
"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"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N",
"baseScore": 4.6,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.1,
"impactScore": 2.5
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-10T14:45:09.952855Z",
"id": "CVE-2026-61456",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
}
],
"references": [
{
"url": "https://github.com/getgrav/grav/security/advisories/GHSA-7vhm-8x52-2r5p",
"source": "[email protected]"
},
{
"url": "https://www.vulncheck.com/advisories/grav-before-stored-xss-via-svg-upload-api",
"source": "[email protected]"
},
{
"url": "https://github.com/getgrav/grav/security/advisories/GHSA-7vhm-8x52-2r5p",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}