What is CVE-2026-86304?
MojoX::Authentication versions before 0.006 for Perl allow SAML authentication bypass because parse_assertion builds Net::SAML2::Binding::POST without a trust anchor. parse_assertion in MojoX::Authentication::Model::SAML2 calls Net::SAML2::Binding::POST->new with no cacert, cert_text or anchors argument, then passes the returned XML to Net::SAML2::Protocol::Assertion->new_from_xml with the IdP signing certificate as cacert. In Net::SAML2 before 0.86 that certificate guards only encrypted assertions, so the signature on an unencrypted assertion is checked against the certificate the response itself carries. An attacker starts a SAML login, then posts a response signed with a certificate of their own. The audience, InResponseTo and timestamp checks that follow are all satisfiable by the attacker, so the response authenticates any NameID it carries.
The record classifies CVE-2026-86304 under weakness class CWE-347. The identifier was first published 29 days ago.
Severity and exploitation probability
- EPSS (FIRST)
- 0.1% probability of exploitation in the next 30 days, higher than 1.1% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Published
- 2026-09-06
Is CVE-2026-86304 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
No affected-product or package list has been recorded for CVE-2026-86304 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.
How to fix CVE-2026-86304
No vendor patch reference has been recorded for CVE-2026-86304 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-86304
No threat campaign in the Threadlinqs corpus currently references CVE-2026-86304, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, GitHub Security Advisories, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.