Twig: Sandbox method allowlist bypass via `Markup` subclass
CVE-2026-46636

8.7HIGH

Key Information:

Vendor

TwigPHP

Status
Twig
Vendor
CVE Published:
4 September 2026

What is CVE-2026-46636?

Twig is a template language for PHP. From version 1.0.0 to before version 3.27.0, SecurityPolicy::checkMethodAllowed() unconditionally whitelists all method calls on instances of Twig\Markup. Twig\Markup is not final, so subclasses inherit the bypass. An application that passes an object of a Markup-derived class into a sandboxed template (typically to mark a chunk of HTML as safe) inadvertently exposes every public method of that subclass to template authors, regardless of the configured allowedMethods list. This issue has been patched in version 3.27.0.

Affected Version(s)

Twig >= 1.0.0, < 3.27.0

References

https://github.com/twigphp/Twig/security/advisories/GHSA-...
x_refsource_CONFIRM
https://security-tracker.debian.org/tracker/CVE-2026-46636
x_refsource_MISC
https://security-tracker.debian.org/tracker/DSA-6311-1
x_refsource_MISC

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.