CVE-2026-9487
XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID.
_get_signed_xml() in lib/XML/Sig.pm, called from verify(), resolves the SignedInfo Reference/@URI to a node with the XPath expression "//*[@ID='$id']" and returns the first node of the resulting node set. A document in which two elements share that ID value is accepted: the digest and signature are checked against whichever element comes first in document order, and the duplicate is not detected.
Such a document verifies successfully while an application that resolves the same ID independently can read the second, attacker supplied element; in a SAML2 context this places the contents of an Assertion under attacker control.
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: 0.28%
- Percentil entre todas las CVEs puntuadas: 18
- Fecha de la puntuación: 4/10/2026
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
T1553.006Code Signing Policy Modificationdefense impairment90 % - Impacto secundario
T1565.001Stored Data Manipulationimpact75 %
Vulnerabilidad de validación XML remota (CWE-347) con AV:N/PR:N/UI:N en versiones de XML::Sig <0.71. Permite falsificación de firmas digitales SAML2 mediante duplicación de atributos ID, comprometiendo integridad de aserciones y confianza en certificados.
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-347
Referencias
JSON original (NVD)
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{
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"timestamp": "2026-08-03T19:59:25.051641Z"
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"published": "2026-08-03T14:16:31.110",
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"value": "XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID.\n\n_get_signed_xml() in lib/XML/Sig.pm, called from verify(), resolves the SignedInfo Reference/@URI to a node with the XPath expression \"//*[@ID='$id']\" and returns the first node of the resulting node set. A document in which two elements share that ID value is accepted: the digest and signature are checked against whichever element comes first in document order, and the duplicate is not detected.\n\nSuch a document verifies successfully while an application that resolves the same ID independently can read the second, attacker supplied element; in a SAML2 context this places the contents of an Assertion under attacker control."
}
],
"lastModified": "2026-08-05T14:57:50.460",
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