CVE-2025-7326 is a high-severity vulnerability identified in Microsoft ASP.NET Core 6.0, specifically related to weak authentication mechanisms. ASP.NET Core 6.0 has reached its End Of Life (EOL) status, meaning Microsoft no longer provides updates or support for this version. The vulnerability is classified under CWE-1390, which pertains to weak authentication. This flaw allows an unauthorized attacker to elevate privileges remotely over a network without requiring user interaction or prior authentication. The CVSS 3.1 base score of 7.0 reflects a high severity, with the vector indicating network attack vector (AV:N), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), low confidentiality and integrity impact (C:L/I:L), but high availability impact (A:H). This suggests that while data confidentiality and integrity are only mildly affected, the vulnerability can cause significant disruption to service availability. No patches or mitigations are provided by Microsoft due to the EOL status of the product, and no known exploits have been reported in the wild yet. The vulnerability affects all versions of ASP.NET Core 6.0 starting from 6.0.0 onward. Given the nature of ASP.NET Core as a widely used web application framework, this vulnerability could be exploited to gain unauthorized elevated privileges, potentially leading to denial of service or further compromise within affected environments. The lack of vendor support and patches increases the risk for organizations continuing to use this EOL software.

For European organizations, the impact of CVE-2025-7326 can be significant, especially for those still running legacy ASP.NET Core 6.0 applications. The ability for an attacker to elevate privileges remotely without authentication or user interaction poses a direct threat to the availability of critical web services. This could lead to service outages, disruption of business operations, and potential cascading effects if the compromised systems are part of larger infrastructure or supply chains. Although confidentiality and integrity impacts are rated low, the availability impact is high, which can affect customer-facing services, internal applications, and critical infrastructure relying on ASP.NET Core 6.0. Additionally, the absence of patches means organizations must rely on alternative mitigations or upgrade paths. European organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often rely on Microsoft technologies, may face increased risk. The threat also raises compliance concerns under regulations like GDPR if service disruptions lead to data processing interruptions or breaches. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future exploitation, especially as attackers often target EOL software due to unpatched vulnerabilities.

Given the absence of official patches from Microsoft for ASP.NET Core 6.0, European organizations should prioritize the following specific mitigation strategies: 1) Immediate upgrade to a supported version of ASP.NET Core (e.g., ASP.NET Core 7.0 or later) that receives security updates and support. 2) Implement network-level protections such as Web Application Firewalls (WAFs) with custom rules to detect and block suspicious authentication attempts or privilege escalation patterns. 3) Employ strict network segmentation to isolate legacy ASP.NET Core 6.0 applications from critical infrastructure and sensitive data stores, limiting the blast radius of any compromise. 4) Enhance monitoring and logging to detect anomalous authentication or privilege escalation activities, enabling rapid incident response. 5) Use multi-factor authentication (MFA) and strong identity and access management (IAM) controls around administrative interfaces and services interacting with ASP.NET Core applications. 6) Conduct thorough application code reviews and penetration testing focused on authentication flows to identify and remediate weak points. 7) If immediate upgrade is not feasible, consider temporary compensating controls such as disabling unnecessary services, restricting inbound network access to trusted IPs, and applying strict firewall rules. 8) Maintain an incident response plan tailored to web application attacks and privilege escalation scenarios. These measures go beyond generic advice by focusing on compensating controls and proactive detection in the absence of vendor patches.