CVE-2025-48877
Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Codepen is present in the default `allowed_iframes` site setting, and it can potentially auto-run arbitrary JS in the iframe scope, which is unintended. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. As a workaround, the Codepen prefix can be removed from a site's `allowed_iframes`.
CVSS
- Versión: 4.0
- Vector: 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:U/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
- Puntuación base: 8.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.41%
- Percentil entre todas las CVEs puntuadas: 33
- 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 access60 %
Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-1038
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-48877",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-48877",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2025-06-09T15:11:20.634452Z"
}
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"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
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 8.1,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"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:U/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",
"exploitMaturity": "UNREPORTED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "discourse",
"product": "discourse",
"versions": [
{
"status": "affected",
"version": "< 3.4.4"
},
{
"status": "affected",
"version": "< 3.5.0.beta5"
},
{
"status": "affected",
"version": "< 3.5.0.beta6-dev"
}
]
}
]
}
],
"published": "2025-06-09T13:15:23.500",
"references": [
{
"url": "https://github.com/discourse/discourse/security/advisories/GHSA-cm93-6m2m-cjcv",
"tags": [
"Vendor Advisory"
],
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-1038"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Codepen is present in the default `allowed_iframes` site setting, and it can potentially auto-run arbitrary JS in the iframe scope, which is unintended. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. As a workaround, the Codepen prefix can be removed from a site's `allowed_iframes`."
},
{
"lang": "es",
"value": "Discourse es una plataforma de discusión de código abierto. En versiones anteriores a la 3.4.4 de la rama `stable`, la 3.5.0.beta5 de la rama `beta` y la 3.5.0.beta6-dev de la rama `tests-passed`, Codepen está presente en la configuración predeterminada del sitio `allowed_iframes` y puede ejecutar automáticamente código JavaScript arbitrario en el ámbito de los iframes, lo cual no es intencionado. Este problema se ha corregido en la 3.4.4 de la rama `stable`, la 3.5.0.beta5 de la rama `beta` y la 3.5.0.beta6-dev de la rama `tests-passed`. Como solución alternativa, se puede eliminar el prefijo Codepen de los `allowed_iframes` de un sitio."
}
],
"lastModified": "2026-06-17T09:30:25.080",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4B5F12D3-D031-4EF6-B122-2F062FEF67B8",
"versionEndExcluding": "3.4.4"
},
{
"criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A0A6583A-A8AE-4C05-8947-79A0E4A73E1D",
"versionEndExcluding": "3.5.0"
},
{
"criteria": "cpe:2.3:a:discourse:discourse:3.5.0:beta1:*:*:beta:*:*:*",
"vulnerable": true,
"matchCriteriaId": "66931995-F794-48F0-9DBB-9048B6C9D8DD"
},
{
"criteria": "cpe:2.3:a:discourse:discourse:3.5.0:beta2:*:*:beta:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B0461B93-273C-4305-80F9-C70A100B4DFE"
},
{
"criteria": "cpe:2.3:a:discourse:discourse:3.5.0:beta3:*:*:beta:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F1596D4E-FD8B-4443-AAAE-1D4AC6B1CE6D"
},
{
"criteria": "cpe:2.3:a:discourse:discourse:3.5.0:beta4:*:*:beta:*:*:*",
"vulnerable": true,
"matchCriteriaId": "997761D0-A8A1-438F-83DE-5E9E4890CEED"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}