Linux Kernel virtio-net/TAP Vulnerability Affects Self-Managed KVM Hypervisors

A critical issue (CVE-2026-99999) in the Linux kernel's virtio-net/TAP networking path affects KVM-based hypervisors running unpatched kernel versions 4.4–6.18. Privileged guest VM users could craft malicious packets to corrupt host kernel memory, potentially leaking sensitive data or causing denial of service. AWS-managed services like EC2, Lambda, and Fargate are safe—no action needed there. However, if you're self-managing VMs with virtio-net and KVM (including Firecracker), you'll want to patch your host kernel ASAP.