Vulnerability-Lookup

GHSA-WQP7-2WW4-Q6MF

Vulnerability from github – Published: 2026-08-03 15:32 – Updated: 2026-08-03 21:31

Details

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.

Severity

9.1 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-9487"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-347"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-03T14:16:31Z",
    "severity": "CRITICAL"
  },
  "details": "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": "GHSA-wqp7-2ww4-q6mf",
  "modified": "2026-08-03T21:31:35Z",
  "published": "2026-08-03T15:32:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9487"
    },
    {
      "type": "WEB",
      "url": "https://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/Changes"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-9487 (GCVE-0-2026-9487)

Vulnerability from cvelistv5 – Published: 2026-08-03 13:14 – Updated: 2026-08-03 19:59

Title

XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID

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.

Severity

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-347 - Improper Verification of Cryptographic Signature

Assigner

CPANSec

References

2 references

URL	Tags
https://github.com/perl-net-saml2/perl-XML-Sig/co…	patch
https://metacpan.org/release/TIMLEGGE/XML-Sig-0.7…	release-notes

Impacted products

1 product

Vendor	Product	Version
TIMLEGGE	XML::Sig	Affected: 0 , < 0.71 (custom)

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "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"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-9487",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-03T19:59:25.051641Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-03T19:59:47.580Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347 Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-03T13:14:43.135Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patch"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/Changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to version 0.71"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID",
      "workarounds": [
        {
          "lang": "en",
          "value": "Signing the outermost \u003csamlp:Response\u003e element rather than only the inner \u003csaml:Assertion\u003e reduces exposure, but does not prevent wrapping variants in which the duplicate ID is introduced outside the signed element. Upgrading to 0.71 is the complete fix."
        }
      ],
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-9487",
    "datePublished": "2026-08-03T13:14:43.135Z",
    "dateReserved": "2026-05-24T13:47:37.954Z",
    "dateUpdated": "2026-08-03T19:59:47.580Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-WQP7-2WW4-Q6MF

CVE-2026-9487 (GCVE-0-2026-9487)

Tags

Sightings

Nomenclature