CVE-2025-27940 is a medium-severity vulnerability affecting Intel's Trusted Domain Extensions (TDX) Module prior to version tdx1.5. The flaw arises from an out-of-bounds read condition within the hypervisor's Ring 0 execution environment, which may allow a software side channel attack to disclose sensitive information. The attack scenario requires a local adversary with privileged user rights on the host system, combined with a high complexity attack vector, but does not require user interaction or special internal knowledge. The vulnerability specifically impacts confidentiality by potentially exposing data from the TDX environment, while integrity and availability remain unaffected. The CVSS 4.0 vector indicates local attack vector (AV:L), high attack complexity (AC:H), privileges required (PR:H), no user interaction (UI:N), and high confidentiality impact (VC:H). No known exploits have been reported in the wild, but the vulnerability poses a risk in environments where privileged users might be compromised or malicious. Intel’s TDX technology is designed to provide hardware-based isolation for virtual machines, so this vulnerability could undermine the confidentiality guarantees of virtualized workloads relying on TDX. The absence of patches in the provided data suggests organizations should monitor Intel advisories closely for updates.

For European organizations, the primary impact is the potential exposure of sensitive data processed within TDX-protected virtual environments. This is particularly critical for sectors handling confidential or regulated data such as finance, healthcare, and government. Since exploitation requires privileged local access, the threat is most relevant in environments where insider threats or compromised privileged accounts are possible. Confidentiality breaches could lead to data leaks, regulatory non-compliance (e.g., GDPR), and reputational damage. The vulnerability does not affect system integrity or availability, so operational disruption is unlikely. However, the undermining of hardware-based isolation could weaken trust in virtualization security models, impacting cloud service providers and enterprises relying on TDX for secure multi-tenant environments. The medium severity rating reflects the complexity and access requirements, but the potential confidentiality impact warrants attention in sensitive European infrastructures.

European organizations should implement the following specific mitigations: 1) Upgrade TDX Modules to version tdx1.5 or later as soon as Intel releases a patch or updated firmware addressing CVE-2025-27940. 2) Restrict and monitor privileged user access rigorously, employing least privilege principles and strong authentication to reduce the risk of local privileged attackers. 3) Employ host-based intrusion detection and behavioral monitoring to detect anomalous activities indicative of side channel exploitation attempts. 4) Isolate critical workloads and sensitive data from environments where privileged user compromise is more likely. 5) Maintain up-to-date inventory of systems using TDX technology to prioritize patching and risk assessment. 6) Collaborate with cloud providers to ensure their TDX implementations are patched and secure. 7) Conduct regular security audits and penetration testing focusing on privileged access controls and side channel attack vectors. These measures go beyond generic advice by focusing on the unique access requirements and attack complexity of this vulnerability.