PT-2026-67393 · Timlegge · Net::Saml2

CVE-2026-18089

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Publicado

2026-08-03

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Atualizado

2026-08-03

CVSS v3.1

7.5

Alta

VetorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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.
verify 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;".
Any 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.

Correção

Improper Certificate Validation

Improper Verification of Cryptographic Signature

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Enumeração de Fraquezas

Identificadores relacionados

CVE-2026-18089

Produtos afetados

Net::Saml2