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CVE-2026-66902

Full vulnerability record from the local CVENow database.

Description

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.

Severity
CRITICAL
CVSS score
9.8 (v3.1)
Vulnerability status
Deferred
Source identifier
9b29abf9-4ab0-4765-b253-1875cd9b441e
Published
2026-08-04 21:16:37.253000
Last modified
2026-10-24 16:10:00.153000
View original CVE JSON
{
  "id": "CVE-2026-66902",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-08-04T21:16:37.253",
  "lastModified": "2026-10-24T16:10:00.153",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call.\n\nThe Pluggable subclass reads credential_source.executable.command from the credentials JSON and runs it as `system($command)`, a single argument call that passes the whole string to /bin/sh -c. The executable's environment_variables map from the same JSON is copied into %ENV first. No opt-in gate guards the call. make_creds selects the Pluggable subclass whenever credential_source.executable is present, so the path is reached from the standard Application Default Credentials flow, including a \"type\": \"external_account\" configuration read from the file named by GOOGLE_APPLICATION_CREDENTIALS. Configurations without credential_source.executable do not select this subclass and do not reach the call.\n\nAny caller that builds credentials from a configuration it does not fully control runs the embedded command with the privileges of the application process."
    },
    {
      "lang": "es",
      "value": "Las versiones de Google::Auth anteriores a la 0.06 para Perl ejecutan un comando especificado en un JSON de credenciales de external_account a través de una llamada al sistema sin control.\n\nLa subclase Pluggable lee credential_source.executable.command del JSON de credenciales y lo ejecuta como ’system($command)’, una llamada de un solo argumento que pasa toda la cadena a /bin/sh -c. El mapa environment_variables del ejecutable del mismo JSON se copia primero en %ENV. Ninguna compuerta de aceptación protege la llamada. make_creds selecciona la subclase Pluggable siempre que credential_source.executable esté presente, por lo que se llega a la ruta desde el flujo estándar de Credenciales Predeterminadas de la Aplicación, incluyendo una configuración ’type’: ’external_account’ leída del archivo especificado por GOOGLE_APPLICATION_CREDENTIALS. Las configuraciones sin credential_source.executable no seleccionan esta subclase y no llegan a la llamada.\n\nCualquier llamador que construya credenciales a partir de una configuración que no controla completamente ejecuta el comando incrustado con los privilegios del proceso de la aplicación."
    }
  ],
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "vendor": "CJCOLLIER",
          "product": "Google::Auth",
          "defaultStatus": "unaffected",
          "collectionURL": "https://cpan.org/modules",
          "packageName": "Google-Auth",
          "programFiles": [
            "lib/Google/Auth/ExternalAccountCredentials/Pluggable.pm"
          ],
          "programRoutines": [
            {
              "name": "Google::Auth::ExternalAccountCredentials::Pluggable::retrieve_subject_token"
            }
          ],
          "repo": "https://github.com/GoogleCloudPlatform/google-auth-library-perl",
          "versions": [
            {
              "version": "0",
              "lessThan": "0.06",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-05T19:27:28.631315Z",
          "id": "CVE-2026-66902",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-78"
        },
        {
          "lang": "en",
          "value": "CWE-829"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/c95c77e70bec94f17e239d88050f843ea1cade95.patch",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://metacpan.org/release/CJCOLLIER/Google-Auth-0.06/diff/CJCOLLIER/Google-Auth-0.05",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/08/04/35",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}