CVE-2026-66902Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call

Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call. The Pluggable subclass reads credential_source.executable.command from the credentials JSON and runs it as `system($command)`, a single argument call that passes the whole string to /bin/sh -c. The executable's environment_variables map from the same JSON is copied into %ENV first. No opt-in gate guards the call. make_creds selects the Pluggable subclass whenever credential_source.executable is present, so the path is reached from the standard Application Default Credentials flow, including a "type": "external_account" configuration read from the file named by GOOGLE_APPLICATION_CREDENTIALS. Configurations without credential_source.executable do not select this subclass and do not reach the call. Any caller that builds credentials from a configuration it does not fully control runs the embedded command with the privileges of the application process.

CVSS

9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness (CWE)

CWE-78, CWE-829

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

CPANSec

NVD analysis

Deferred

Record last updated

Aug 5, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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