CVE-2026-18089

{"id": "CVE-2026-18089", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18089", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-03T19:56:09.872860Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"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"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "affectedData": [{"repo": "https://github.com/perl-net-saml2/perl-Net-SAML2", "vendor": "TIMLEGGE", "product": "Net::SAML2", "versions": [{"status": "affected", "version": "0", "lessThan": "0.86", "versionType": "custom"}], "packageName": "Net-SAML2", "programFiles": ["lib/Net/SAML2/Role/VerifyXML.pm", "lib/Net/SAML2/Binding/POST.pm", "lib/Net/SAML2/Protocol/Assertion.pm"], "collectionURL": "https://cpan.org/modules", "defaultStatus": "unaffected", "programRoutines": [{"name": "Net::SAML2::Role::VerifyXML::verify_xml"}, {"name": "Net::SAML2::Binding::POST::handle_response"}, {"name": "Net::SAML2::Protocol::Assertion::_verify_encrypted_assertion"}]}]}], "published": "2026-08-03T14:16:24.890", "references": [{"url": "https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Binding/POST.pm#L21", "tags": ["Product"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Protocol/Assertion.pm#L84", "tags": ["Product"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.85/source/lib/Net/SAML2/Role/VerifyXML.pm#L32", "tags": ["Product"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://metacpan.org/release/TIMLEGGE/Net-SAML2-0.88/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-295"}, {"lang": "en", "value": "CWE-347"}]}], "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."}], "lastModified": "2026-08-06T18:36:40.763", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:timlegge:net\\:\\:saml2:*:*:*:*:*:perl:*:*", "vulnerable": true, "matchCriteriaId": "69FF1709-62F7-4E8C-B90D-ABFA96B07FF1", "versionEndExcluding": "0.86"}], "operator": "OR"}]}], "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}