Critical Flaw in samlify Exposes SSO to Attack

EXECUTIVE SUMMARY:

A critical vulnerability, CVE-2025-47949 with a CVSS score of 9.9, affects all versions of the samlify library prior to v2.10.0, exposing countless SAML-based Single Sign-On (SSO) systems to SAML Signature Wrapping (SSW) attacks. This flaw allows attackers to forge SAML responses by injecting unsigned assertions into signed XML documents, enabling them to impersonate any user and bypass authentication entirely. Widely used in enterprise environments, samlify sees over 768,000 monthly downloads, making the potential impact severe—facilitating unauthorized access, privilege escalation, and lateral movement. All users are urged to upgrade to version v2.10.0 or later immediately.