FKIE_CVE-2026-9487

Vulnerability from fkie_nvd - Published: 2026-08-03 14:16 - Updated: 2026-08-05 14:57
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Summary
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.
References
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patchPatch
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/ChangesRelease Notes
Impacted products
Vendor Product Version
xml\ \ sig_project
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "XML-Sig",
          "product": "XML::Sig",
          "programFiles": [
            "lib/XML/Sig.pm"
          ],
          "programRoutines": [
            {
              "name": "XML::Sig::verify"
            },
            {
              "name": "XML::Sig::_get_signed_xml"
            }
          ],
          "repo": "https://github.com/perl-net-saml2/perl-XML-Sig",
          "vendor": "TIMLEGGE",
          "versions": [
            {
              "lessThan": "0.71",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:xml\\:\\:sig_project:xml\\:\\:sig:*:*:*:*:*:perl:*:*",
              "matchCriteriaId": "FC1BDEFE-0662-4F7C-9641-A32B9CF06366",
              "versionEndExcluding": "0.71",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "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=\u0027$id\u0027]\" 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."
    }
  ],
  "id": "CVE-2026-9487",
  "lastModified": "2026-08-05T14:57:50.460",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-9487",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-03T19:59:25.051641Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-03T14:16:31.110",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "tags": [
        "Release Notes"
      ],
      "url": "https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/Changes"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-347"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}



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