CVE-2026-77633 Cloudreve: Storage-quota TOCTOU race allows quota bypass and storage-based denial of service

Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, PrepareUpload in pkg/filemanager/fs/dbfs/upload.go checks a stale in-memory user storage value through validateUserCapacity and later applies an unconditional storage charge outside the same quota-enforcing transactio...