An issue was discovered in OpenStack Nova before 30.2.2, 31 before 31.2.1, and 32 before 32.1.1. By writing a malicious QCOW header to a root or ephemeral disk and then triggering a resize, a user may convince Nova's Flat image backend to call qemu-img without a format restriction, resulting in an unsafe image resize operation that could destroy data on the host system. Only compute nodes using the Flat image backend (usually configured with use_cow_images=False) are affected.
{
"cwe_ids": [
"CWE-669"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-19T20:27:55Z",
"nvd_published_at": "2026-02-18T18:24:33Z",
"severity": "HIGH"
}