{
   "document": {
      "aggregate_severity": {
         "text": "high"
      },
      "category": "csaf_security_advisory",
      "csaf_version": "2.0",
      "distribution": {
         "tlp": {
            "label": "WHITE",
            "url": "https://www.first.org/tlp/"
         }
      },
      "lang": "en",
      "notes": [
         {
            "category": "description",
            "text": "XML::Sig versions from 0.29 before 0.72 for Perl allow signature verification bypass because verify returns true when every signature was skipped before any cryptographic check.\n\nverify in lib/XML/Sig.pm counts the `//dsig:Signature` elements into `$numsigs` and iterates over them, but two paths reach `next` before any digest or key check runs: a `SignedInfo/Reference/@URI` that resolves to no element while `$numsigs` is greater than 1, and, when `id_attr` is set, a reference that does not match the requested ID. The loop records nothing about what it checked, so when every signature takes one of those paths control reaches the unconditional `return 1` that ends verify. Two `Signature` elements whose Reference URI names an ID that no element carries is enough, as is one such element combined with `id_attr`.\n\nAny caller that passes untrusted XML to verify can receive a true return for a document in which no digest and no signature value was checked; a `cert` or `cert_text` trust anchor does not change this, because no key check runs. Versions up to 0.28 use an XML::XPath based verify that has no such skip and are not affected.",
            "title": "Vulnerability Description"
         }
      ],
      "publisher": {
         "category": "other",
         "contact_details": "gdt@cpan.org",
         "name": "giterlizzi",
         "namespace": "https://github.com/giterlizzi/"
      },
      "references": [
         {
            "category": "self",
            "summary": "CPANSA-XML-Sig-2026-18568 JSON",
            "url": "https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-xml-sig-2026-18568.json"
         },
         {
            "category": "external",
            "summary": "https://github.com/perl-net-saml2/perl-XML-Sig/commit/ef22cfed1ac0f29b316d17eb79cf6480e03ae16a.patch",
            "url": "https://github.com/perl-net-saml2/perl-XML-Sig/commit/ef22cfed1ac0f29b316d17eb79cf6480e03ae16a.patch"
         },
         {
            "category": "external",
            "summary": "https://metacpan.org/release/TIMLEGGE/XML-Sig-0.72/changes",
            "url": "https://metacpan.org/release/TIMLEGGE/XML-Sig-0.72/changes"
         },
         {
            "category": "external",
            "summary": "https://www.cve.org/CVERecord?id=CVE-2025-40934",
            "url": "https://www.cve.org/CVERecord?id=CVE-2025-40934"
         },
         {
            "category": "external",
            "summary": "CVE-2026-18568 (NVD)",
            "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18568"
         }
      ],
      "title": "XML-Sig vulnerability",
      "tracking": {
         "current_release_date": "2026-08-03T00:00:00",
         "generator": {
            "engine": {
               "name": "CSAF Perl Toolkit",
               "version": "0.26"
            }
         },
         "id": "CPANSA-XML-Sig-2026-18568",
         "initial_release_date": "2026-08-03T00:00:00",
         "revision_history": [
            {
               "date": "2026-08-03T00:00:00",
               "number": "1",
               "summary": "First release"
            }
         ],
         "status": "final",
         "version": "1"
      }
   },
   "product_tree": {
      "branches": [
         {
            "branches": [
               {
                  "category": "product_version_range",
                  "name": "vers:cpan/>=0.29",
                  "product": {
                     "name": "XML-Sig greater than or equal 0.29",
                     "product_id": "CSAFPID-0001",
                     "product_identification_helper": {
                        "purl": "pkg:cpan/XML-Sig"
                     }
                  }
               },
               {
                  "category": "product_version_range",
                  "name": "vers:cpan/<0.72",
                  "product": {
                     "name": "XML-Sig less than 0.72",
                     "product_id": "CSAFPID-0002",
                     "product_identification_helper": {
                        "purl": "pkg:cpan/XML-Sig"
                     }
                  }
               }
            ],
            "category": "product_name",
            "name": "XML-Sig"
         }
      ]
   },
   "vulnerabilities": [
      {
         "cve": "CVE-2026-18568",
         "cwe": {
            "id": "CWE-347",
            "name": "Improper Verification of Cryptographic Signature"
         },
         "notes": [
            {
               "category": "description",
               "text": "XML::Sig versions from 0.29 before 0.72 for Perl allow signature verification bypass because verify returns true when every signature was skipped before any cryptographic check.\n\nverify in lib/XML/Sig.pm counts the `//dsig:Signature` elements into `$numsigs` and iterates over them, but two paths reach `next` before any digest or key check runs: a `SignedInfo/Reference/@URI` that resolves to no element while `$numsigs` is greater than 1, and, when `id_attr` is set, a reference that does not match the requested ID. The loop records nothing about what it checked, so when every signature takes one of those paths control reaches the unconditional `return 1` that ends verify. Two `Signature` elements whose Reference URI names an ID that no element carries is enough, as is one such element combined with `id_attr`.\n\nAny caller that passes untrusted XML to verify can receive a true return for a document in which no digest and no signature value was checked; a `cert` or `cert_text` trust anchor does not change this, because no key check runs. Versions up to 0.28 use an XML::XPath based verify that has no such skip and are not affected.",
               "title": "Vulnerability Description"
            }
         ],
         "product_status": {
            "fixed": [
               "CSAFPID-0002"
            ],
            "known_affected": [
               "CSAFPID-0001"
            ]
         },
         "scores": [
            {
               "cvss_v3": {
                  "baseScore": 7.5,
                  "baseSeverity": "HIGH",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
                  "version": "3.1"
               },
               "products": [
                  "CSAFPID-0001"
               ]
            }
         ]
      }
   ]
}