CVE-2026-25748
authentik is an open-source identity provider. Prior to 2025.10.4 and 2025.12.4, with a malformed cookie it was possible to bypass authentication when using forward authentication in the authentik Proxy Provider when used in conjunction with Traefik or Caddy as reverse proxy. When a malicious cookie was used, none of the authentik-specific X-Authentik-* headers were set which depending on application can grant access to an attacker. authentik 2025.10.4 and 2025.12.4 fix this issue.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.78%
- Percentil entre todas las CVEs puntuadas: 55
- 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
T1078Valid Accountsstealth · persistence · privilege escalation · initial access90 %
Vulnerabilidad de bypass de autenticación (CWE-287) en servicio expuesto en red sin autenticación previa (AV:N/PR:N/UI:N). Permite acceso no autorizado mediante cookie malformada.
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)
CWE
- CWE-287
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-25748",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-25748",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-02-17T15:52:54.989237Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 8.6,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 4,
"exploitabilityScore": 3.9
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "goauthentik",
"product": "authentik",
"versions": [
{
"status": "affected",
"version": ">= 2025.10.0-rc1, < 2025.10.4"
},
{
"status": "affected",
"version": ">= 2025.10.0-rc1, < 2025.12.4"
}
]
}
]
}
],
"published": "2026-02-12T20:16:10.473",
"references": [
{
"url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2025.10.4",
"tags": [
"Product",
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.4",
"tags": [
"Product",
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/goauthentik/authentik/security/advisories/GHSA-fj56-5763-j8pp",
"tags": [
"Vendor Advisory"
],
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-287"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "authentik is an open-source identity provider. Prior to 2025.10.4 and 2025.12.4, with a malformed cookie it was possible to bypass authentication when using forward authentication in the authentik Proxy Provider when used in conjunction with Traefik or Caddy as reverse proxy. When a malicious cookie was used, none of the authentik-specific X-Authentik-* headers were set which depending on application can grant access to an attacker. authentik 2025.10.4 and 2025.12.4 fix this issue."
},
{
"lang": "es",
"value": "authentik es un proveedor de identidad de código abierto. Antes de las versiones 2025.10.4 y 2025.12.4, con una cookie malformada era posible eludir la autenticación al usar la autenticación de reenvío en el Proveedor de Proxy de authentik cuando se utilizaba junto con Traefik o Caddy como proxy inverso. Cuando se utilizaba una cookie maliciosa, ninguno de los encabezados X-Authentik-* específicos de authentik se establecía, lo que, dependiendo de la aplicación, podía conceder acceso a un atacante. authentik 2025.10.4 y 2025.12.4 solucionan este problema."
}
],
"lastModified": "2026-06-17T10:25:09.800",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D68BD58B-CB50-411F-862F-FF4F4F984239",
"versionEndExcluding": "2025.10.4"
},
{
"criteria": "cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A59D4BC9-5FAE-4A4F-A109-D754BD80A10C",
"versionEndExcluding": "2025.12.4",
"versionStartIncluding": "2025.12.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}