CVE-2026-15158
The Blocksy Companion plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.1.46 via the save_attachments function. This is due to the Custom Fonts extension registering a wp_check_filetype_and_ext filter that approves any filename containing .woff2 or .ttf as a substring via strpos() rather than validating that those strings appear as the final extension via PATHINFO_EXTENSION — allowing double-extension filenames such as shell.woff2.php to pass MIME validation and be handled as permitted font files.
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This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. This vulnerability is only exploitable when the premium version of the plugin (blocksy-companion-pro) is installed with both the WooCommerce Extra (Advanced Reviews) and Custom Fonts extensions active; the free blocksy-companion plugin does not contain the vulnerable code paths.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.07%
- Percentil entre todas las CVEs puntuadas: 64
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1505.003Web Shellpersistence90 % - Impacto secundario
T1059Command and Scripting Interpreterexecution85 %
AV:N/PR:N/UI:N indica acceso remoto sin autenticación (T1190). La subida de archivos .php enmascarados permite crear web shells (T1505.003) y ejecutar comandos arbitrarios (T1059).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-434
Referencias
- https://plugins.trac.wordpress.org/browser/blocksy-companion/tags/2.1.46/framework/premium/extensions/custom-fonts/extension.php#L137
- https://plugins.trac.wordpress.org/browser/blocksy-companion/tags/2.1.46/framework/premium/extensions/woocommerce-extra/features/advanced-reviews/feature.php#L811
- https://www.wordfence.com/threat-intel/vulnerabilities/id/2df449b4-3f3b-4afc-b391-8d8d11710c07?source=cve
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-15158",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-15158",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-07-09T13:52:33.878936Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security@wordfence.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security@wordfence.com",
"affectedData": [
{
"vendor": "creativethemeshq",
"product": "Blocksy Companion",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "2.1.46"
}
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-07-09T10:16:25.370",
"references": [
{
"url": "https://plugins.trac.wordpress.org/browser/blocksy-companion/tags/2.1.46/framework/premium/extensions/custom-fonts/extension.php#L137",
"source": "security@wordfence.com"
},
{
"url": "https://plugins.trac.wordpress.org/browser/blocksy-companion/tags/2.1.46/framework/premium/extensions/woocommerce-extra/features/advanced-reviews/feature.php#L811",
"source": "security@wordfence.com"
},
{
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/2df449b4-3f3b-4afc-b391-8d8d11710c07?source=cve",
"source": "security@wordfence.com"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security@wordfence.com",
"description": [
{
"lang": "en",
"value": "CWE-434"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The Blocksy Companion plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.1.46 via the save_attachments function. This is due to the Custom Fonts extension registering a wp_check_filetype_and_ext filter that approves any filename containing .woff2 or .ttf as a substring via strpos() rather than validating that those strings appear as the final extension via PATHINFO_EXTENSION — allowing double-extension filenames such as shell.woff2.php to pass MIME validation and be handled as permitted font files. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. This vulnerability is only exploitable when the premium version of the plugin (blocksy-companion-pro) is installed with both the WooCommerce Extra (Advanced Reviews) and Custom Fonts extensions active; the free blocksy-companion plugin does not contain the vulnerable code paths."
}
],
"lastModified": "2026-07-09T16:19:45.567",
"sourceIdentifier": "security@wordfence.com"
}