In nspawn in systemd 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40226.json",
"cna_assigner": "mitre",
"cwe_ids": [
"CWE-348"
]
}