CVE-2026-4851 | GRID::Machine versions through 0.127 for Perl allows arbitrary code execution via unsafe deserialization
GRID::Machine versions through 0.127 for Perl allows arbitrary code execution via unsafe deserialization.
GRID::Machine provides Remote Procedure Calls (RPC) over SSH for Perl. The client connects to remote hosts to execute code on them. A compromised or malicious remote host can execute arbitrary code back on the client through unsafe deserialization in the RPC protocol.
read_operation() in lib/GRID/Machine/Message.pm deserialises values from the remote side using eval()
$arg .= '$VAR1';
my $val = eval "no strict; $arg"; # line 40-41
$arg is raw bytes from the protocol pipe. A compromised remote host can embed arbitrary perl in the Dumper-formatted response:
$VAR1 = do { system("..."); };
This executes on the client silently on every RPC call, as the return values remain correct.
This functionality is by design but the trust requirement for the remote host is not documented in the distribution.
Conclusion & alert: CVE-2026-4851 is rated Moderate Risk (52.5/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.47%).Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2026-4851
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).