dbcve.org
Grid\Application · Casiano

CVE-2026-4851

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-29
Fix available
A fix is available. Upgrade to after 0.127 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

GRID::Machine versions through 0.127 use unsafe deserialization in read_operation() (lib/GRID/Machine/Message.pm lines 40-41), where eval() deserializes Dumper-formatted data from remote hosts. A compromised or malicious remote host can embed arbitrary Perl code (e.g., system() calls) within the serialized response that silently executes on the client with every RPC call.

MitigationAvoid using GRID::Machine with untrusted remote hosts; replace the unsafe eval() deserialization with a safe parser (e.g., using JSON instead of Data::Dumper, or a restricted eval sandbox), or migrate to a secure RPC alternative.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Grid\Application
Affected:<= 0.127

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify GRID::Machine is installed
    Run: perl -MGRID::Machine -e 'print $GRID::Machine::VERSION . "\n"'
    Affected if Version exists and is <= 0.127 (the module is installed)
  2. Check if the vulnerable Message.pm exists
    Locate the module: perl -e 'use lib::abs qw(lib); print $INC{"GRID/Machine/Message.pm"} // "not found"' and inspect lines 40-41 for eval() usage on Dumper data
    Affected if The file exists and contains eval() deserializing Data::Dumper output (vulnerable code path present)
  3. Identify applications using GRID::Machine for remote connections
    Search codebase for: use GRID::Machine; or require GRID::Machine; followed by remote host connection calls (e.g., $machine = GRID::Machine->new(host => ...))
    Affected if Code uses GRID::Machine to connect to remote hosts, enabling the deserialization attack surface
  4. Audit remote host configurations
    Review configuration files or scripts that specify remote hostnames/IPs passed to GRID::Machine->new()
    Affected if Remote hosts are specified, meaning untrusted or compromised remote machines could send malicious serialized responses

You are affected if GRID::Machine <= 0.127 is installed and your code uses it to connect to remote hosts, as the eval() deserialization in read_operation() will execute arbitrary code embedded in responses from those hosts.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 0.127
Interim mitigation

Avoid using GRID::Machine with untrusted remote hosts; replace the unsafe eval() deserialization with a safe parser (e.g., using JSON instead of Data::Dumper, or a restricted eval sandbox), or migrate to a secure RPC alternative.

Fix this in Grid\ Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-4851 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4851 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data