CVE-2026-86304
MojoX::Authentication versions before 0.006 for Perl allow SAML authentication bypass because parse_assertion builds Net::SAML2::Binding::POST without a trust anchor.
parse_assertion in MojoX::Authentication::Model::SAML2 calls Net::SAML2::Binding::POST->new with no cacert, cert_text or anchors argument, then passes the returned XML to Net::SAML2::Protocol::Assertion->new_from_xml with the IdP signing certificate as cacert. In Net::SAML2 before 0.86 that certificate guards only encrypted assertions, so the signature on an unencrypted assertion is checked against the certificate the response itself carries.
Leer descripción completaMostrar menos
An attacker starts a SAML login, then posts a response signed with a certificate of their own. The audience, InResponseTo and timestamp checks that follow are all satisfiable by the attacker, so the response authenticates any NameID it carries.
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: 0.31%
- Percentil entre todas las CVEs puntuadas: 22
- 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 access92 % - Impacto principal
T1078Valid Accountsstealth · persistence · privilege escalation · initial access90 % - Impacto secundario
T1556Modify Authentication Processdefense impairment · persistence · credential access85 %
Red sin privilegios (AV:N/PR:N) permite bypass de autenticación SAML explotando falta de verificación de certificados (CWE-347). Atacante puede falsificar respuestas SAML firmadas con certificados propios, autenticándose como cualquier usuario (T1078) y potencialmente modificar configuración de aute
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 (2)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-347
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-86304",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-86304",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-09-08T18:41:21.191743Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
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"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
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"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"modules": [
"MojoX::Authentication"
],
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "0.006",
"versionType": "custom"
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"packageURL": "pkg:cpan/MojoX-Authentication",
"packageName": "MojoX-Authentication",
"programFiles": [
"lib/MojoX/Authentication/Model/SAML2.pm"
],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
{
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"published": "2026-09-06T23:17:39.483",
"references": [
{
"url": "https://metacpan.org/release/POLETTIX/MojoX-Authentication-0.004/source/lib/MojoX/Authentication/Model/SAML2.pm#L188",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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"url": "https://metacpan.org/release/POLETTIX/MojoX-Authentication-0.006/source/Changes",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://www.cve.org/CVERecord?id=CVE-2026-18089",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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],
"vulnStatus": "Deferred",
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"description": [
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"value": "CWE-347"
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"descriptions": [
{
"lang": "en",
"value": "MojoX::Authentication versions before 0.006 for Perl allow SAML authentication bypass because parse_assertion builds Net::SAML2::Binding::POST without a trust anchor.\n\nparse_assertion in MojoX::Authentication::Model::SAML2 calls Net::SAML2::Binding::POST->new with no cacert, cert_text or anchors argument, then passes the returned XML to Net::SAML2::Protocol::Assertion->new_from_xml with the IdP signing certificate as cacert. In Net::SAML2 before 0.86 that certificate guards only encrypted assertions, so the signature on an unencrypted assertion is checked against the certificate the response itself carries.\n\nAn attacker starts a SAML login, then posts a response signed with a certificate of their own. The audience, InResponseTo and timestamp checks that follow are all satisfiable by the attacker, so the response authenticates any NameID it carries."
}
],
"lastModified": "2026-09-08T19:20:13.933",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}