CVE-2026-18089: Improper Verification of Cryptographic Signature

Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the response-embedded certificate in verifyxml when no trust anchor is configured. verifyxml in Net::SAML2::Role::VerifyXML runs "return if !$anchors && !$cacert;" as soon as the XML::Sig chec...