Which versions of Intel TDX Module are affected by EUVD-2026-56505?

Intel's Trust Domain Extensions (TDX) vulnerability (CVE-2026-20885) enables hypervisor-privileged attackers to breach confidential-computing isolation boundaries, potentially exposing sensitive…

How to fix or mitigate EUVD-2026-56505?

Within 24 hours: Inventory all systems running Intel TDX and document deployment context including hypervisor platform and workload sensitivity classification. Within 7 days: Assess threat scope by identifying confidential workloads on affected TDX systems and coordinate with infrastructure teams on hypervisor access hardening options. Within 30 days: Implement compensating controls including hypervisor management plane isolation, credential rotation for hypervisor administrators, enhanced monitoring for suspicious Ring-0 activity, and evaluation of workload migration to alternative confidential-computing platforms or segregated infrastructure for highest-sensitivity operations.

Intel TDX Module EUVD-2026-56505

Q: What is the CVSS score of EUVD-2026-56505?

EUVD-2026-56505 has a CVSS 4.0 base score of 7.0 (High). CVSS vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.1%.

| CVE-2026-20885 HIGH

Improper Authentication (CWE-287)

2026-08-11 intel

GHSA-9cwm-qgv5-93vq

Authentication Bypass Privilege Escalation Information Disclosure Intel N A Intel R Platforms

7.0

CVSS 4.0 · Vendor: intel

Severity by source

Vendor (intel) PRIMARY

7.0 HIGH

CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

7.2 HIGH

Local-only attack requiring Ring-0 privileges and high complexity; scope changes because TDX Trust Domain isolation boundary is crossed; no availability impact per description.

3.1 AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N

4.0 AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N

Primary rating from Vendor (intel).

CVSS VectorVendor: intel

Attack Vector

Local

Attack Complexity

High

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Aug 11, 2026 - 17:32 vuln.today

CVE Published

Aug 11, 2026 - 16:26 cve.org

HIGH 7.0

DescriptionCVE.org

Improper authentication in the Intel(R) TDX module for some Intel(R) platforms within Ring 0: Trust Domain may allow an information disclosure and escalation of privilege. System software adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (low), integrity (low) and availability (none) impacts.

AnalysisAI

Improper authentication (CWE-287) in Intel's Trust Domain Extensions (TDX) module allows a Ring-0 system software adversary with high privileges to breach Trust Domain isolation boundaries, enabling information disclosure and privilege escalation. Affects select Intel platforms running TDX with a high-complexity, locally-executed attack path - no user interaction required. No public exploit identified at time of analysis, but the confidential-computing trust model is fundamentally undermined if exploited: an adversary with hypervisor-level access could read or modify memory intended to be protected from exactly that privilege tier.

Technical ContextAI

Intel TDX (Trust Domain Extensions) is a hardware-assisted confidential computing technology, introduced with 4th-gen Intel Xeon Scalable ('Sapphire Rapids') platforms, that creates cryptographically isolated virtual machine environments called Trust Domains (TDs). The TDX Module itself runs at a new privilege level (SEAM, Secure Arbitration Mode) conceptually above Ring 0, acting as a security monitor between the host hypervisor and tenant TDs. CWE-287 (Improper Authentication) in this context indicates the TDX module fails to properly verify the identity or authorization of a calling Ring-0 entity before granting operations affecting TD state or data. The CPE string (cpe:2.3:a:n/a:intel(r)_platforms:*:*:*:*:*:*:*:*) is non-specific, but Intel's advisory INTEL-SA-01436 scopes this to 'some Intel platforms', indicating a subset of TDX-capable systems. The CVSS 4.0 attack requirement flag AT:P confirms that specific platform or configuration preconditions must be met.

RemediationAI

The primary remediation is to apply the updated Intel TDX Module (firmware/microcode update) identified in Intel Security Advisory INTEL-SA-01436 at https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01436.html. Platform vendors (OEMs, CSPs) typically distribute TDX module updates via BIOS/UEFI firmware updates or OS-level microcode update packages - check your platform vendor's support portal for applicable firmware releases. An exact fixed module version is not independently confirmable from the available data; consult INTEL-SA-01436 directly for the authoritative fix version. As a compensating control pending patching, consider restricting or auditing Ring-0/hypervisor-level access to TDX-capable platforms, and treat any unauthorized access to the hypervisor layer as a full compromise of co-located TDs. Disabling TDX in the BIOS eliminates the attack surface entirely but also removes all confidential computing protections for tenant workloads - this trade-off is only appropriate where TDX is not operationally required.