Out-of-Bounds Write in Linux kernel (CVE-2026-31470)
Summary
Out-of-bounds write in Linux kernel (CVE-2026-31470). Confidential information can be exposed externally. Exploitable via quote_buf.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-31470 has been found in Linux kernel.
Attackers can target a specific entry point like quote_buf over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-31470" on the vendor's site.
CVE-2026-31470 (Linux kernel) — CWE-787 / CVSS v3 7.1
Attack vector: local / no user interaction
Attack surface: quote_buf
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds write (CWE-787) exists in Linux kernel. Attackers reach the vulnerable code path via quote_buf.
Check the vendor advisory for the affected versions of Linux kernel. Attack surface: quote_buf.
Severity: High (CVSS 7.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-31470 linux-lts Fixed in: 6.12.80-r0
- Debian DEBIAN-CVE-2026-31470 linux Fixed in: 6.12.85-1
- Ubuntu UBUNTU-CVE-2026-31470 linux-hwe-edge
References
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org