CVE-2026-27969: Vitess users with backup storage access can write to arbitrary file paths on restore

Anyone with read/write access to the backup storage location (e.g. an S3 bucket) can manipulate backup manifest files so that files in the manifest — which may be files that they have also added to the manifest and backup contents — are written to any accessible location on restore. This is a common Path Traversal security issue. This can be used to provide that attacker with unintended/unauthorized access to the production deployment environment — allowing them to access information available in that environment as well as run any additional arbitrary commands there.