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

{
  "id": "987aae45f3069c8714a85ba7b869253a84488b052bb452e0e00f068d95cc2cff",
  "url": "https://osv.dev/vulnerability/CVE-2026-66902",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call",
    "summary": "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.",
    "evidence": "osv:CVE-2026-66902",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-66902",
      "aliases": [
        "CVE-2026-66902"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/googlecloudplatform/google-auth-library-perl",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "c95c77e70bec94f17e239d88050f843ea1cade95"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "c95c77e70bec94f17e239d88050f843ea1cade95"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66902.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.934886882Z",
      "provider": "osv",
      "references": [
        "https://cpan.org/modules",
        "https://metacpan.org/release/CJCOLLIER/Google-Auth-0.06/diff/CJCOLLIER/Google-Auth-0.05",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66902.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-66902",
        "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/c95c77e70bec94f17e239d88050f843ea1cade95.patch",
        "https://github.com/GoogleCloudPlatform/google-auth-library-perl"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-78",
          "CWE-829"
        ],
        "cna_assigner": "CPANSec",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "0.06"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "0.06"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66902.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-66902",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493572,
  "published_at": "2026-08-04T20:49:43.171+00:00"
}