{"id":"GHSA-mm6w-gr99-p3jj","aliases":["CVE-2026-46639"],"title":"Twig: Sandbox property and method bypass via object-destructuring assignment","description":"### Description\n\nThe object-destructuring assignment syntax introduced in Twig 3.24.0 generates a call to `CoreExtension::getAttribute()` with the `$sandboxed` argument hardcoded to `false`, regardless of whether a `SandboxExtension` is active. This permanently disables the sandbox's property and method policy checks for every destructuring expression.\n\n`ObjectDestructuringSetBinary::compile()` emits:\n\n```php\nCoreExtension::getAttribute($this->env, $this->source, ..., \\Twig\\Template::ANY_CALL, false, false, false, ...);\n//                                                                                ^^^^^\n//                                                                       sandbox check never runs\n```\n\nWhereas `GetAttrExpression::compile()` correctly passes `$env->hasExtension(SandboxExtension::class)`.\n\nAn attacker with write access to a sandboxed Twig template can read any public property or invoke any public getter on objects passed to the template engine, bypassing `SecurityPolicy` restrictions. The exploit requires only the `{% do %}` tag to be in `allowedTags`, which is a common configuration.\n\n### Resolution\n\nThe destructuring compiler now forwards the active sandbox flag to `getAttribute()` so property/method allowlists are enforced.\n\n### Credits\n\nTwig would like to thank Anvil Secure in collaboration with Claude and Anthropic Research for reporting and fixing the issue.","severity":"high","score":8.7,"published":"2026-05-21T21:30:49.000Z","modified":"2026-09-10T03:51:06.512Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Packagist","name":"twig/twig","ranges":[{"events":[{"introduced":"3.24.0"},{"fixed":"3.26.0"}],"type":"ECOSYSTEM"}],"versions":["v3.24.0","v3.25.0"],"fixed":["3.26.0"]}],"references":["https://github.com/twigphp/Twig/security/advisories/GHSA-mm6w-gr99-p3jj","https://github.com/FriendsOfPHP/security-advisories/blob/master/twig/twig/CVE-2026-46639.yaml","https://github.com/twigphp/Twig","https://symfony.com/cve-2026-46639"],"sources":[{"name":"OSV","id":"GHSA-mm6w-gr99-p3jj","modified":"2026-09-10T03:51:06.512482823Z","url":"https://osv.dev/vulnerability/GHSA-mm6w-gr99-p3jj"}],"assessments":[{"source":"OSV","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":8.7}]}