CVE-2026-61800: Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893)

Wazuh is an open-source security platform providing unified XDR and SIEM protection for endpoints and cloud workloads. In versions 4.4.0 through 4.14.6, a party holding the cluster key can write, overwrite, or delete arbitrary files under /var/ossec on worker nodes, leading to remote code execution as root. During cluster file synchronization, the non-merged branch of updatemasterfilesinworker() moves each staged file to a destination derived only from safejoin(), which confines the path to /var/ossec but never verifies that the file lands in the directory declared by its clusteritemkey. Because the destination check present on the primary node and on the worker's merged branch was not applied, a peer can place files at attacker-chosen locations under /var/ossec, including paths that are executed as root, and the delete branch has the same gap. This is an incomplete fix for CVE-2026-30893, which addressed traversal outside /var/ossec but left this path able to redirect files anywhere within it. This issue is fixed in version 4.14.7.