{"api_version":"1","generated_at":"2026-08-06T20:40:41+00:00","cve":"CVE-2026-18089","urls":{"html":"https://cve.report/CVE-2026-18089","api":"https://cve.report/api/cve/CVE-2026-18089.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-18089","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-18089"},"summary":{"title":"Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verify_xml when no trust anchor is configured","description":"Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verify_xml when no trust anchor is configured.\n\nverify_xml in Net::SAML2::Role::VerifyXML runs \"return if !$anchors && !$cacert;\" as soon as the XML::Sig check succeeds, and that check uses the X.509 certificate taken from the response's own dsig:KeyInfo/dsig:X509Certificate element, so an unanchored response is checked only against the key it carries. Binding::POST declares cacert as an optional Maybe[Str] with no default, so a POST binding built without one takes that path, and _verify_encrypted_assertion returns early the same way with \"return $xml unless $cacert;\".\n\nAny caller that constructs Binding::POST or calls Assertion->new_from_xml without a cacert, cert_text, or anchors argument accepts a response signed by an attacker generated key whose self-signed certificate is embedded in that response, authenticating an arbitrary assertion.","state":"PUBLISHED","assigner":"CPANSec","published_at":"2026-08-03 14:16:24","updated_at":"2026-08-06 18:36:40"},"problem_types":["CWE-295","CWE-347","CWE-347 CWE-347 Improper Verification of Cryptographic Signature","CWE-295 CWE-295 Improper Certificate Validation"],"metrics":[{"version":"3.1","source":"ADP","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}},{"version":"3.1","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"}}],"references":[{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Protocol/Assertion.pm#L84","name":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Protocol/Assertion.pm#L84","refsource":"9b29abf9-4ab0-4765-b253-1875cd9b441e","tags":["Product"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.88/source/Changes","name":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.88/source/Changes","refsource":"9b29abf9-4ab0-4765-b253-1875cd9b441e","tags":["Release Notes"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Binding/POST.pm#L21","name":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Binding/POST.pm#L21","refsource":"9b29abf9-4ab0-4765-b253-1875cd9b441e","tags":["Product"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Role/VerifyXML.pm#L32","name":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Role/VerifyXML.pm#L32","refsource":"9b29abf9-4ab0-4765-b253-1875cd9b441e","tags":["Product"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-18089","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18089","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"TIMLEGGE","product":"Net::SAML2","version":"affected 0.86 custom","platforms":[]}],"timeline":[{"source":"CNA","time":"2026-07-31T00:00:00.000Z","lang":"en","value":"Version 0.86 released with fix."},{"source":"CNA","time":"2026-07-31T00:00:00.000Z","lang":"en","value":"Version 0.88 released, re-issuing 0.86 with a corrected version number."}],"solutions":[{"source":"CNA","title":"","value":"Upgrade to Net::SAML2 0.86 or later, which requires a cacert or cert_text trust anchor before a response or assertion signature is verified.","time":"","lang":"en"}],"workarounds":[{"source":"CNA","title":"","value":"For deployments that cannot upgrade, construct Net::SAML2::Binding::POST, and call Net::SAML2::Protocol::Assertion->new_from_xml, with a cacert, cert_text, or anchors argument identifying the IdP signing certificate.","time":"","lang":"en"}],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"18089","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"timlegge","cpe5":"net\\","cpe6":"\\","cpe7":"saml2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"perl"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"18089","cve":"CVE-2026-18089","epss":"0.001750000","percentile":"0.072130000","score_date":"2026-08-05","updated_at":"2026-08-06 00:00:38"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}},{"other":{"content":{"id":"CVE-2026-18089","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-08-03T19:56:09.872860Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-08-03T19:56:33.033Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://cpan.org/modules","defaultStatus":"unaffected","packageName":"Net-SAML2","product":"Net::SAML2","programFiles":["lib/Net/SAML2/Role/VerifyXML.pm","lib/Net/SAML2/Binding/POST.pm","lib/Net/SAML2/Protocol/Assertion.pm"],"programRoutines":[{"name":"Net::SAML2::Role::VerifyXML::verify_xml"},{"name":"Net::SAML2::Binding::POST::handle_response"},{"name":"Net::SAML2::Protocol::Assertion::_verify_encrypted_assertion"}],"repo":"https://github.com/perl-net-saml2/perl-Net-SAML2","vendor":"TIMLEGGE","versions":[{"lessThan":"0.86","status":"affected","version":"0","versionType":"custom"}]}],"descriptions":[{"lang":"en","value":"Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verify_xml when no trust anchor is configured.\n\nverify_xml in Net::SAML2::Role::VerifyXML runs \"return if !$anchors && !$cacert;\" as soon as the XML::Sig check succeeds, and that check uses the X.509 certificate taken from the response's own dsig:KeyInfo/dsig:X509Certificate element, so an unanchored response is checked only against the key it carries. Binding::POST declares cacert as an optional Maybe[Str] with no default, so a POST binding built without one takes that path, and _verify_encrypted_assertion returns early the same way with \"return $xml unless $cacert;\".\n\nAny caller that constructs Binding::POST or calls Assertion->new_from_xml without a cacert, cert_text, or anchors argument accepts a response signed by an attacker generated key whose self-signed certificate is embedded in that response, authenticating an arbitrary assertion."}],"impacts":[{"capecId":"CAPEC-115","descriptions":[{"lang":"en","value":"CAPEC-115 Authentication Bypass"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","description":"CWE-347 Improper Verification of Cryptographic Signature","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-295","description":"CWE-295 Improper Certificate Validation","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-03T12:42:08.879Z","orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","shortName":"CPANSec"},"references":[{"tags":["release-notes"],"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.88/source/Changes"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Role/VerifyXML.pm#L32"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Binding/POST.pm#L21"},{"url":"https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Protocol/Assertion.pm#L84"}],"solutions":[{"lang":"en","value":"Upgrade to Net::SAML2 0.86 or later, which requires a cacert or cert_text trust anchor before a response or assertion signature is verified."}],"source":{"discovery":"UNKNOWN"},"timeline":[{"lang":"en","time":"2026-07-31T00:00:00.000Z","value":"Version 0.86 released with fix."},{"lang":"en","time":"2026-07-31T00:00:00.000Z","value":"Version 0.88 released, re-issuing 0.86 with a corrected version number."}],"title":"Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verify_xml when no trust anchor is configured","workarounds":[{"lang":"en","value":"For deployments that cannot upgrade, construct Net::SAML2::Binding::POST, and call Net::SAML2::Protocol::Assertion->new_from_xml, with a cacert, cert_text, or anchors argument identifying the IdP signing certificate."}],"x_generator":{"engine":"cpansec-cna-tool 0.1"}}},"cveMetadata":{"assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","assignerShortName":"CPANSec","cveId":"CVE-2026-18089","datePublished":"2026-08-03T12:42:08.879Z","dateReserved":"2026-07-28T16:26:10.967Z","dateUpdated":"2026-08-03T19:56:33.033Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-03 14:16:24","lastModifiedDate":"2026-08-06 18:36:40","problem_types":["CWE-295","CWE-347","CWE-347 CWE-347 Improper Verification of Cryptographic Signature","CWE-295 CWE-295 Improper Certificate Validation"],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-03T19:56:09.872860Z","id":"CVE-2026-18089","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:timlegge:net\\:\\:saml2:*:*:*:*:*:perl:*:*","versionEndExcluding":"0.86","matchCriteriaId":"69FF1709-62F7-4E8C-B90D-ABFA96B07FF1"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"18089","Ordinal":"1","Title":"Net::SAML2 versions before 0.86 for Perl allow SAML authenticati","CVE":"CVE-2026-18089","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"18089","Ordinal":"1","NoteData":"Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verify_xml when no trust anchor is configured.\n\nverify_xml in Net::SAML2::Role::VerifyXML runs \"return if !$anchors && !$cacert;\" as soon as the XML::Sig check succeeds, and that check uses the X.509 certificate taken from the response's own dsig:KeyInfo/dsig:X509Certificate element, so an unanchored response is checked only against the key it carries. Binding::POST declares cacert as an optional Maybe[Str] with no default, so a POST binding built without one takes that path, and _verify_encrypted_assertion returns early the same way with \"return $xml unless $cacert;\".\n\nAny caller that constructs Binding::POST or calls Assertion->new_from_xml without a cacert, cert_text, or anchors argument accepts a response signed by an attacker generated key whose self-signed certificate is embedded in that response, authenticating an arbitrary assertion.","Type":"Description","Title":"Net::SAML2 versions before 0.86 for Perl allow SAML authenticati"}]}}}