CVE-2026-71243
The backmeup npm package assembles shell command strings by directly concatenating its option values (name, source, destination, filter) - e.g. cmd = "mkdir -p " + path.join(info.destination, info.name) + "; " - and executes the resulting string through a shell via ssh2-exec (locally via child_process, or remotely via SSH when an ssh handle is supplied), rather than using execFile/spawn with an argument array. The only processing applied is path.normalize()/path.join(), which do not neutralize shell metacharacters (;, |, &, $(), backticks, newline). Any application that passes attacker-influenced values into these options (e.g. a user-chosen backup name) is vulnerable to arbitrary OS command execution on the backup host, or on the remote SSH target when one is configured.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 8.8 HIGH
Vector: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.