GHSA-mm6w-gr99-p3jj

Source

https://github.com/advisories/GHSA-mm6w-gr99-p3jj

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-mm6w-gr99-p3jj/GHSA-mm6w-gr99-p3jj.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-mm6w-gr99-p3jj

Aliases

CVE-2026-46639

Published

2026-05-21T21:30:49Z

Modified

2026-05-21T21:45:17.837589880Z

Severity

8.7 (High) 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 CVSS Calculator

Summary

Twig: Sandbox property and method bypass via object-destructuring assignment

Details

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:

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.

Database specific

{
    "cwe_ids": [
        "CWE-693"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-21T21:30:49Z",
    "nvd_published_at": null,
    "severity": "HIGH"
}

References

Affected packages

Packagist / twig/twig

Package

Name: twig/twig
Purl: pkg:composer/twig%2Ftwig

Affected ranges

Type: ECOSYSTEM
Events: Introduced

3.24.0

Fixed

3.26.0

Affected versions

v3.*

v3.24.0

v3.25.0

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-mm6w-gr99-p3jj/GHSA-mm6w-gr99-p3jj.json"