Formwork before 2.3.13 contains a path traversal vulnerability in BackupController that allows authenticated panel users to read or delete arbitrary files. Attackers with backup download or delete permission can supply a base64-encoded backslash-separated traversal payload that bypasses PHP basename on Linux to access files outside the backup directory.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-22"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104478.json"
}