Out-of-Bounds Write in Amazon Linux kernel's virtio-net/TAP networking path (CVE-2026-99999)
Summary
Out-of-bounds write in Amazon Linux kernel's virtio-net/TAP networking path (CVE-2026-99999). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
Bulletin ID: 2026-137-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/15/2026 10:30 AM PDT Description: AWS is aware of an issue in the Linux kernel's virtio-net/TAP networking path (CVE-2026-99999) that affects KVM-based hypervisors running unpatched Linux kernel versions 4.4 through 6.18. This issue could allow an actor with privileged access inside a guest virtual machine to send specially crafted network packets that corrupt host kernel memory that could result in disclosure of host memory or a denial of service. AWS-managed compute and container services, including Amazon EC2 instances, AWS Lambda, and AWS Fargate, are not affected. There is no action required for customers using these services. Affected products & versions: Customers who self-manage virtual machines using virtio-net and KVM, including those using virtual machine monitors such as Firecracker, on hosts running affected, unpatched Linux kernel versions. Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
Source: AWS Security Bulletins 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-2026-99999 has been found in Amazon Linux kernel's virtio-net/TAP networking path.
Successful exploitation can lead to full system takeover. CVSS score: 9.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Amazon Linux kernel's virtio-net/TAP networking path CVE-2026-99999" on the vendor's site.
CVE-2026-99999 (Amazon Linux kernel's virtio-net/TAP networking path) — CWE-787 / CVSS v3 9.3
Attack vector: local / unauthenticated / no user interaction
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 Amazon Linux kernel's virtio-net/TAP networking path.
Check the vendor advisory for the affected versions of Amazon Linux kernel's virtio-net/TAP networking path.
Severity: Critical (CVSS 9.3/10). Successful exploitation can lead to full system takeover.
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
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Amazon Linux kernel's virtio-net/TAP networking path を使っているサービスとバージョンを洗い出す。
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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。
References
- AWS aws.amazon.com
- REDHAT Red Hat
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web pwn.ai
- web vercel.com
- web openwall.com