GHSA-mm6w-gr99-p3jj
Twig: Sandbox property and method bypass via object-destructuring assignment
En bref
- Publiée
- Mise à jour
- CVE
- CVE-2026-46639
- CVSS_V4
- 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
Description
### Description The object-destructuring assignment syntax introduced in Twig 3.24.0 generates a call to `CoreExtension::getAttribute()` with the `$sandboxed` argument hardcoded to `false`, regardless of whether a `SandboxExtension` is active. This permanently disables the sandbox's property and method policy checks for every destructuring expression. `ObjectDestructuringSetBinary::compile()` emits: ```php CoreExtension::getAttribute($this->env, $this->source, ..., \Twig\Template::ANY_CALL, false, false, false, ...); // ^^^^^ // sandbox check never runs ``` Whereas `GetAttrExpression::compile()` correctly passes `$env->hasExtension(SandboxExtension::class)`. An 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. ### Resolution The destructuring compiler now forwards the active sandbox flag to `getAttribute()` so property/method allowlists are enforced. ### Credits Twig would like to thank Anvil Secure in collaboration with Claude and Anthropic Research for reporting and fixing the issue.
Paquets affectés
| Paquet | Versions |
|---|---|
| Packagist · twig/twig | introduced 3.24.0, fixed 3.26.0 |
Références
- https://github.com/twigphp/Twig/security/advisories/GHSA-mm6w-gr99-p3jj WEB
- https://github.com/FriendsOfPHP/security-advisories/blob/master/twig/twig/CVE-2026-46639.yaml WEB
- https://github.com/twigphp/Twig PACKAGE
- https://symfony.com/cve-2026-46639 WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |