CVE-2025-20623 is a medium-severity vulnerability affecting Intel Core processors of the 10th generation. The issue arises from the shared microarchitectural predictor state within these processors, which influences transient execution. Specifically, this shared predictor state can be manipulated by an authenticated local user to potentially disclose sensitive information. The vulnerability exploits the speculative execution features of modern CPUs, where transient instructions executed speculatively may leave observable side effects that can be leveraged to infer confidential data. Since the attack requires local authenticated access, it is not exploitable remotely or by unauthenticated users. The vulnerability does not require user interaction beyond authentication and has a CVSS 4.0 base score of 5.7, reflecting a medium impact primarily on confidentiality. The vulnerability does not affect integrity or availability, and no known exploits are currently reported in the wild. Intel has reserved the CVE and published the details, but no specific patches or mitigations have been linked yet. This vulnerability is part of a class of transient execution side-channel attacks that have been a concern since Spectre and Meltdown disclosures, but this particular issue is limited to a specific generation of Intel CPUs and requires local privilege, reducing its attack surface compared to remote or unauthenticated vulnerabilities.

For European organizations, the impact of CVE-2025-20623 depends largely on the deployment of Intel 10th generation Core processors within their infrastructure. Since the vulnerability allows an authenticated local user to potentially disclose sensitive information, environments where multiple users share the same physical machine or where low-privileged users have local access (e.g., shared workstations, virtualized environments, or developer machines) are at higher risk. Confidentiality breaches could lead to exposure of sensitive corporate data, intellectual property, or personal data protected under GDPR. However, the requirement for local authentication and the absence of remote exploitation vectors limit the risk to insider threats or attackers who have already gained some level of access. Critical infrastructure and sectors with high-value data, such as finance, healthcare, and government, may face increased risk if these processors are widely used. The lack of known exploits in the wild reduces immediate threat levels, but organizations should remain vigilant given the potential for future exploitation. Overall, the impact is moderate but significant in environments with shared access or where insider threat risk is elevated.

To mitigate CVE-2025-20623, European organizations should implement a combination of hardware, software, and operational controls beyond generic advice. First, inventory and identify all systems running Intel 10th generation Core processors to assess exposure. Apply any available microcode updates or firmware patches from Intel as soon as they become available, as these often address microarchitectural vulnerabilities. In the absence of patches, consider disabling hyper-threading or speculative execution features where feasible, understanding the performance trade-offs. Enforce strict access controls to limit local authenticated user access only to trusted personnel, and employ robust endpoint security solutions to detect and prevent privilege escalation attempts. Use virtualization isolation techniques to separate workloads and reduce shared resource contention. Regularly audit user accounts and monitor for unusual local access patterns. Additionally, implement data encryption at rest and in use to reduce the impact of potential data disclosure. Finally, maintain up-to-date threat intelligence and be prepared to deploy patches promptly once released.