CVE-2025-7326 is a high-severity vulnerability classified under CWE-1390, which pertains to weak authentication mechanisms. This vulnerability affects Microsoft ASP.NET Core versions 6.0.0 and later, specifically those that have reached their End Of Life (EOL) status. The weakness allows an unauthorized attacker to elevate privileges remotely over a network without requiring any user interaction or prior authentication. The CVSS 3.1 base score of 7.0 reflects a high severity, with the attack vector being network-based (AV:N), high attack complexity (AC:H), no privileges required (PR:N), and no user interaction needed (UI:N). The impact scope is unchanged (S:U), with low confidentiality and integrity impacts but a high impact on availability (C:L/I:L/A:H). The vulnerability arises from weak authentication controls in the EOL ASP.NET Core components, which could allow attackers to bypass authentication checks and gain elevated privileges. Since these components are no longer supported by Microsoft, no patches or updates are available to remediate this issue, increasing the risk for organizations still running these versions. The lack of known exploits in the wild currently suggests limited active exploitation, but the potential for future attacks remains, especially targeting legacy systems. Given that ASP.NET Core is widely used for web application development, this vulnerability could be exploited to compromise web servers, leading to denial of service or unauthorized access to sensitive resources. The absence of patches means organizations must rely on alternative mitigation strategies to protect their environments.

For European organizations, the impact of CVE-2025-7326 can be significant, particularly for those still operating legacy or EOL ASP.NET Core environments. Exploitation could lead to service disruptions due to availability impacts, unauthorized privilege escalation, and potential lateral movement within networks. This could affect critical business applications, customer-facing portals, and internal systems, resulting in operational downtime, reputational damage, and potential regulatory non-compliance under GDPR if personal data confidentiality or integrity is compromised. The high availability impact could disrupt essential services, especially in sectors like finance, healthcare, and government, where ASP.NET Core is commonly used. The lack of vendor support complicates incident response and remediation efforts, increasing the risk exposure for European enterprises.

Since no patches or updates are available for this EOL vulnerability, European organizations should implement compensating controls. These include: 1) Immediate inventory and identification of all ASP.NET Core instances running EOL versions; 2) Plan and execute migration to supported ASP.NET Core versions (post-EOL) that receive security updates; 3) Employ network segmentation and strict firewall rules to limit external and internal access to vulnerable servers; 4) Implement strong network-level authentication and multi-factor authentication on all access points to reduce unauthorized access risk; 5) Use Web Application Firewalls (WAFs) with custom rules to detect and block suspicious authentication bypass attempts; 6) Monitor logs and network traffic for anomalous activities indicative of privilege escalation attempts; 7) Conduct regular security assessments and penetration testing focusing on authentication mechanisms; 8) Establish incident response plans tailored to address exploitation of authentication weaknesses; 9) Educate developers and system administrators about the risks of running unsupported software and the importance of timely upgrades.