{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-18568","assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","state":"PUBLISHED","assignerShortName":"CPANSec","dateReserved":"2026-08-02T00:59:21.745Z","datePublished":"2026-08-03T14:38:52.540Z","dateUpdated":"2026-08-03T20:05:52.443Z"},"containers":{"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"}],"repo":"https://github.com/perl-net-saml2/perl-XML-Sig","vendor":"TIMLEGGE","versions":[{"lessThan":"0.72","status":"affected","version":"0.29","versionType":"custom"}]}],"descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","description":"CWE-347 Improper Verification of Cryptographic Signature","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","shortName":"CPANSec","dateUpdated":"2026-08-03T14:38:52.540Z"},"references":[{"tags":["patch"],"url":"https://github.com/perl-net-saml2/perl-XML-Sig/commit/ef22cfed1ac0f29b316d17eb79cf6480e03ae16a.patch"},{"tags":["release-notes"],"url":"https://metacpan.org/release/TIMLEGGE/XML-Sig-0.72/changes"},{"tags":["related"],"url":"https://www.cve.org/CVERecord?id=CVE-2025-40934"}],"solutions":[{"lang":"en","value":"Upgrade to XML::Sig 0.72 or later, which returns false when no reference digest was checked and matched."}],"source":{"discovery":"UNKNOWN"},"timeline":[{"lang":"en","time":"2026-08-03T00:00:00.000Z","value":"Version 0.72 released with fix."}],"title":"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","x_generator":{"engine":"cpansec-cna-tool 0.1"}},"adp":[{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-08-03T20:05:13.814301Z","id":"CVE-2026-18568","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-03T20:05:52.443Z"}}]}}