CVE-2025-5456 is a high-severity buffer over-read vulnerability (CWE-125) affecting multiple Ivanti products, including Ivanti Connect Secure, Ivanti Policy Secure, Ivanti ZTA Gateway, and Ivanti Neurons for Secure Access. The vulnerability exists in versions prior to 22.7R2.8 or 22.8R2 for Connect Secure, 22.7R1.5 for Policy Secure, 2.8R2.3-723 for ZTA Gateway, and 22.8R1.4 for Neurons for Secure Access. This flaw allows a remote unauthenticated attacker to trigger a denial of service (DoS) condition by causing the affected software to perform an out-of-bounds read operation. The vulnerability is classified under CWE-125, which involves reading memory outside the bounds of a buffer, potentially leading to application crashes or system instability. The CVSS v3.1 base score is 7.5, indicating a high severity level, with the vector showing that the attack can be performed remotely (AV:N) with low attack complexity (AC:L), no privileges required (PR:N), no user interaction needed (UI:N), and impacts availability only (A:H) without affecting confidentiality or integrity. The vulnerability was publicly disclosed on August 12, 2025, with fixes deployed on August 2, 2025. No known exploits in the wild have been reported yet. The affected Ivanti products are commonly used for secure remote access, policy enforcement, zero trust access, and network security management, making this vulnerability particularly relevant for organizations relying on these solutions for secure connectivity and access control.

For European organizations, the impact of CVE-2025-5456 can be significant due to the widespread use of Ivanti's secure access and policy enforcement products in enterprise environments. A successful exploitation could lead to denial of service conditions, disrupting remote access capabilities and potentially halting critical business operations that depend on secure VPN or zero trust gateways. This disruption could affect employee productivity, remote workforce connectivity, and access to internal resources. Although the vulnerability does not directly compromise confidentiality or integrity, the loss of availability in security gateways can indirectly increase risk exposure by forcing organizations to rely on less secure fallback mechanisms or causing delays in security monitoring and incident response. Sectors such as finance, healthcare, government, and critical infrastructure in Europe, which often use Ivanti products for secure access, could face operational downtime and compliance challenges, especially under stringent regulations like GDPR that mandate continuous protection of data and services.

European organizations should immediately verify their Ivanti product versions and apply the security patches released on August 2, 2025, to remediate this vulnerability. Since no known exploits are reported yet, proactive patch management is critical. Network administrators should also implement network-level protections such as firewall rules to restrict access to Ivanti management interfaces and VPN gateways to trusted IP ranges only. Monitoring and logging of Ivanti product access should be enhanced to detect unusual traffic patterns or repeated connection attempts that might indicate exploitation attempts. Additionally, organizations should conduct vulnerability scans and penetration tests focusing on Ivanti products to ensure no residual exposure remains. Employing segmentation to isolate Ivanti gateways from other critical network segments can limit the impact of potential DoS attacks. Finally, maintaining up-to-date incident response plans that include scenarios for denial of service on secure access infrastructure will improve readiness to respond effectively.