{"id":"GHSA-mc5q-6hpj-rp7j","summary":"Grav: Twig sandbox config exfiltration via grav.offsetGet + dump filter (CVE-2026-44738 bypass)","details":"### Summary\n\nThe Twig content sandbox replaces `config` with the redacted `SandboxConfig` facade and strips `Config::get`/`toArray` from the method allowlist (GHSA-j274-39qw-32c9), so editor content can't read config secrets via `config`. That's bypassable: `grav` is the raw container, `offsetget` is allow-listed on it, so `grav.offsetGet('config')` returns the real `Config`. The allow-listed filters `json_encode`/`print_r`/`yaml_encode` then serialize it at the PHP level, never hitting the sandbox method gate, dumping the whole config tree including every `plugins.*` secret (SMTP creds, API keys, plugin DB creds). Incomplete fix for GHSA-j274-39qw-32c9. `security.salt` does not leak (it lives outside config).\n\n### Details\n\nThe documented path is blocked: `config` is the `SandboxConfig` facade (`Twig.php:660`) and the raw `Config`/`Data` method entries are stripped when `config_access` is false, so `{{ config.get(...) }}` returns the default and `{{ grav.offsetGet('config').get(...) }}` raises `SecurityNotAllowedMethodError`.\n\nThe bypass uses two allow-listed primitives the redaction doesn't cover:\n\n1. `grav.offsetGet('config')` returns the raw `Config`. The `SandboxConfig` facade replaces only the `config` variable, not `grav['config']`; `offsetget` is allow-listed on `Grav\\Common\\Grav` in `system/config/security.yaml`.\n2. `json_encode`/`print_r`/`yaml_encode` serialize the object inside the filter and never call `GravSecurityPolicy::checkMethodAllowed` (`GravSecurityPolicy.php:65`), so the stripped methods don't matter.\n\nBug class: object-dumping filters bypass the sandbox member gate. The same dump reaches `page`/`pages`/`uri`/`user` via their allow-listed accessors; `config` is the secret-bearing target.\n\nReachable below the publisher-Twig opt-in: a `_`-prefixed slug is modular (`Page.php:228`), and `Page::content()` sets `$process_twig = $scan_twig_xss || $this-\u003emodularTwig()` (`Page.php:816`), so a modular child's body Twig is sandboxed-rendered even with `twig_content.process_enabled` false (the default), while `$scan_twig_xss` stays false so the render-time XSS scan (GHSA-2c4f-86xc-cr74) is skipped. Any `admin.pages` author (or filesystem write to `user/pages`) exfiltrates config on a stock install. On a regular `process.twig` page the whole-tree dump trips the XSS scan and is blanked, but a targeted `split`/`slice` extraction of one subtree is XSS-clean and survives.\n\n### PoC\n\nSandboxed render, `config_access` default false. First two lines show the gate holding, third is the bypass:\n\n```twig\n{{ config.get('plugins.email.mailer.smtp.password', 'DENIED') }}\n{# =\u003e DENIED #}\n{{ grav.offsetGet('config').get('plugins.email.mailer.smtp.password') }}\n{# =\u003e SecurityNotAllowedMethodError 'get' #}\n{{ grav.offsetGet('config')|json_encode }}\n{# =\u003e {...,\"plugins\":{\"email\":{\"mailer\":{\"smtp\":{\"password\":\"CANARY...\"}}}},...} #}\n```\n\nStock-install reproduction (no `user/config/security.yaml`):\n\n```yaml\n# user/config/plugins/email.yaml  -- decoy secret\nmailer: { smtp: { password: CANARY_SMTP_PW_8b3f1 } }\n```\n\n```\n# user/pages/70.parent/default.md\n---\ntitle: Parent\ncontent: { items: '@self.modular' }\ntemplate: modular\n---\n```\n\n```twig\n{# user/pages/70.parent/_secret/default.md #}\n---\ntitle: Secret\ntemplate: modular/text\n---\n{{ grav.offsetGet('config')|json_encode }}\n```\n\n```bash\ncurl -s http://localhost/parent   # body contains CANARY_SMTP_PW_8b3f1\n```\n\n`logs/security.log` shows no sandbox block and no XSS scan for the route. Verified on Grav 2.0.1 (6f619f0ae), PHP 8.4.22, Twig 3.26.1-DEV.\n\n### Impact\n\nA page author (`admin.pages`, no admin/super) reads the entire config tree: plugin SMTP credentials, API keys, plugin DB credentials. Read-only. Default install; the modular path needs no Twig opt-in.\n\n### Fix\n\n`system/config/security.yaml`: drop `offsetget` (and `__get`) from `twig_sandbox.allowed_methods` for `Grav\\Common\\Grav` -- the legit uses are `theme`/`getversion`; `offsetget` is the raw-container reach. Closes the demonstrated path.\n\nSandbox-wide: make `json_encode`/`print_r`/`yaml_encode`/`string` refuse non-allow-listed objects when `$env-\u003eisSandboxed()` (mirror the Closure-only guard Twig applies to `map`/`filter`/`reduce`). Closes the class for `page`/`pages`/`uri`/`user` too.","aliases":["CVE-2026-61450","CVE-2026-61842"],"modified":"2026-09-02T21:45:10.838430889Z","published":"2026-09-02T21:41:12Z","database_specific":{"nvd_published_at":"2026-08-19T16:18:17Z","cwe_ids":["CWE-200"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-09-02T21:41:12Z"},"references":[{"type":"WEB","url":"https://github.com/getgrav/grav/security/advisories/GHSA-mc5q-6hpj-rp7j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61842"},{"type":"WEB","url":"https://github.com/getgrav/grav/commit/7efe70574e4cf01a251318478c13673029e93eb6"},{"type":"PACKAGE","url":"https://github.com/getgrav/grav"},{"type":"WEB","url":"https://github.com/getgrav/grav/releases/tag/2.0.2"}],"affected":[{"package":{"name":"getgrav/grav","ecosystem":"Packagist","purl":"pkg:composer/getgrav/grav"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.2"}]}],"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"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-mc5q-6hpj-rp7j/GHSA-mc5q-6hpj-rp7j.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"}]}