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 v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patch	Patch
https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/Changes	Release Notes

Configurations

Configuration 1 (hide)

cpe:2.3:a:xml\:\:sig_project:xml\:\:sig:*:*:*:*:*:perl:*:*

History

No history.

Information

Published : 2026-08-03 14:16

Updated : 2026-08-05 14:57

NVD link : CVE-2026-9487

Mitre link : CVE-2026-9487

CVE.ORG link : CVE-2026-9487

JSON object : View

Products Affected

xml\

\

CWE

CWE-347

Improper Verification of Cryptographic Signature

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