CVE-2026-48807: Twig: Sandbox `__toString()` policy bypass via `Traversable` in `join` and `replace` filters

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-14 · updated 2026-10-24
Weakness: CWE-693

Description

Twig is a template language for PHP. Prior to 3.27.0, the sandbox __toString() checks do not fully cover Traversable values passed to join and replace filters or operands evaluated by the in and not in operators, allowing contained Stringable objects to be coerced to strings without consulting the sandbox policy. This issue is fixed in version 3.27.0.

Affected products

twigphp Twig: before 3.27.0 — fixed in 3.27.0

How to fix

Upgrade to a fixed version: twigphp Twig 3.27.0. Check the vendor advisory for mitigations.

References

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