CVE-2026-31470

About vulnerability

In the Linux kernel, the following vulnerability has been resolved: virt: tdx-guest: Fix handling of host controlled ‘quote’ buffer length Validate host controlled value quote_buf->out_len that determines how many bytes of the quote are copied out to guest userspace. In TDX environments with remote attestation, quotes are not considered private, and can be forwarded to an attestation server. Catch scenarios where the host specifies a response length larger than the guest’s allocation, or otherwise races modifying the response while the guest consumes it. This prevents contents beyond the pages allocated for quote_buf (up to TSM_REPORT_OUTBLOB_MAX) from being read out to guest userspace, and possibly forwarded in attestation requests. Recall that some deployments want per-container configs-tsm-report interfaces, so the leak may cross container protection boundaries, not just local root. A flaw was found in the Linux kernel’s TDX guest virtualization component. A malicious host can manipulate the ‘quote’ buffer length, allowing it to specify a response length larger than the guest’s allocated memory. This can lead to information disclosure, where sensitive data beyond the intended buffer can be read by guest userspace and potentially forwarded in attestation requests, which are used to verify the integrity of the virtual machine.

Live-patch status from KernelCare for each operating system.