CVE-2026-15747
Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle.
_csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle.
An attacker able to query it can recover the token and pass csrf_protect validation.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Puntuación base: 9.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.25%
- Percentil entre todas las CVEs puntuadas: 15
- Fecha de la puntuación: 6/10/2026
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 access85 % - Impacto principal
T1212Exploitation for Credential Accesscredential access90 % - Impacto secundario
T1090Proxycommand and control70 %
Vulnerabilidad remota de oráculo de compresión (BREACH) en Mojolicious que expone tokens CSRF predecibles sin autenticación (AV:N/PR:N/UI:N); permite recuperar credenciales de sesión y eludir protecciones CSRF para manipular solicitudes.
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-204, CWE-352
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-15747",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-15747",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-07-15T16:31:33.252608Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.1,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"repo": "https://github.com/mojolicious/mojo",
"vendor": "SRI",
"product": "Mojolicious",
"versions": [
{
"status": "affected",
"version": "4.59",
"lessThan": "9.48",
"versionType": "custom"
}
],
"packageName": "Mojolicious",
"programFiles": [
"lib/Mojolicious/Plugin/DefaultHelpers.pm",
"lib/Mojolicious/Plugin/TagHelpers.pm",
"lib/Mojolicious/Renderer.pm"
],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "Mojolicious::Plugin::DefaultHelpers::_csrf_token"
}
]
}
]
}
],
"published": "2026-07-14T18:17:12.587",
"references": [
{
"url": "https://github.com/mojolicious/mojo/commit/01921fbbbbeca2d1397e082d4a647f9b84c24e27.patch",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://metacpan.org/release/SRI/Mojolicious-9.48/changes",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "http://www.openwall.com/lists/oss-security/2026/07/14/16",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"description": [
{
"lang": "en",
"value": "CWE-204"
},
{
"lang": "en",
"value": "CWE-352"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle.\n\n_csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle.\n\nAn attacker able to query it can recover the token and pass csrf_protect validation."
}
],
"lastModified": "2026-07-15T20:08:42.780",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}