Veeam has patched a critical flaw in Backup and Replication, one of the most widely deployed enterprise backup tools, that lets any authenticated low-privilege domain user run code remotely on the backup server. The bug (CVE-2026-44963, rated 9.4) only affects version 12 installations joined to an Active Directory domain; version 13, which uses a different architecture, is not affected, and workgroup setups are safe. No exploitation has been seen yet, but Veeam warns attackers often move quickly once patches reveal the flaw, and backup servers are a prime ransomware target because compromising them cripples recovery. The fix is build 12.3.2.4854.