CVE-2026-31470 Details
Description
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 vulnerability in the Linux kernel's TDX guest handling has been addressed. This issue involved improper management of a host-controlled 'quote' buffer length, which could lead to unintended data exposure. In TDX environments with remote attestation, quotes can be forwarded to an attestation server and are not considered private. The vulnerability allowed contents beyond the allocated pages for the quote buffer to be read into guest userspace, potentially leaking information across container boundaries. The issue has been fixed by validating the length of the response before it is sent to the guest, ensuring that only the allocated bytes are copied and preventing any overflow or unauthorized data access.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched version are available in the Linux kernel documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/02ca2d9d197723696cb9cc0cb159eb7e8bf5f89b | kernel.org | Patch |
| https://git.kernel.org/stable/c/6f3c8795ae9ba74fa10fe979293d1904712d3fb1 | kernel.org | Patch |
| https://git.kernel.org/stable/c/a079a62883e3365de592cea9f7a669d8115433b0 | kernel.org | Patch |
| https://git.kernel.org/stable/c/c3fd16c3b98ed726294feab2f94f876290bf7b61 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-787 | Out-of-bounds Write | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.7, < 6.12.80 >= 6.13, < 6.18.21 >= 6.19, < 6.19.11 7.0 rc1 7.0 rc2 7.0 rc3 7.0 rc4 7.0 rc5 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| May 7, 2026 | Initial Analysis | [email protected] |
| Apr 27, 2026 | CVE Modified | kernel.org |
| Apr 22, 2026 | New CVE Received | kernel.org |