CVE-2025-46784 is a vulnerability classified under CWE-401 (Improper Release of Memory Before Removing Last Reference) affecting Entr'ouvert Lasso version 2.5.1, specifically in the function lasso_node_init_from_message_with_format. Lasso is a library used for SAML (Security Assertion Markup Language) processing, commonly employed in federated identity and single sign-on (SSO) solutions. The vulnerability occurs when the function processes a specially crafted SAML response that leads to improper memory handling, causing memory depletion. This memory exhaustion results in denial of service (DoS), as the application may crash or become unresponsive due to resource exhaustion. The vulnerability is remotely exploitable without any authentication or user interaction, increasing its risk profile. The CVSS v3.1 base score is 7.5 (high), reflecting the network vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability (no confidentiality or integrity impact). No patches were linked at the time of publication, and no known exploits are reported in the wild. The vulnerability highlights the importance of secure memory management in parsing complex XML-based protocols like SAML, where malformed inputs can lead to resource exhaustion attacks.

For European organizations, the primary impact of CVE-2025-46784 is the potential disruption of authentication services relying on Entr'ouvert Lasso 2.5.1 for SAML processing. Denial of service in identity federation components can lead to widespread access issues, preventing legitimate users from authenticating and accessing critical applications. This can affect business continuity, especially in sectors with high dependency on SSO such as government, finance, healthcare, and large enterprises. The unavailability of authentication services may also increase helpdesk workload and operational costs. Since the vulnerability does not impact confidentiality or integrity, data breaches are unlikely; however, service outages can indirectly affect compliance with regulations like GDPR if service availability is critical. The ease of exploitation without authentication or user interaction means attackers can launch automated attacks at scale, potentially targeting multiple organizations simultaneously. The lack of known exploits currently provides a window for proactive mitigation before active exploitation emerges.

1. Monitor Entr'ouvert's official channels for patches addressing CVE-2025-46784 and apply them promptly once available. 2. Implement strict input validation and sanity checks on incoming SAML responses before processing to detect and reject malformed or suspicious messages. 3. Deploy rate limiting and anomaly detection on SAML endpoints to mitigate potential flooding or memory exhaustion attacks. 4. Consider isolating or sandboxing the Lasso processing component to limit the impact of a DoS attack on the broader system. 5. Maintain up-to-date logging and monitoring to detect unusual spikes in memory usage or service crashes related to SAML processing. 6. If immediate patching is not possible, evaluate temporary mitigations such as disabling vulnerable SAML features or using alternative SAML libraries. 7. Conduct security reviews of SAML integration points and ensure secure coding practices are followed to prevent similar memory management issues.