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.

Twig is a template language for PHP. Prior to 3.27.0, deprecated internal wrappers in src/Resources/core.php do not forward the current sandbox state to CoreExtension::checkArrow(), arraySome(), and arrayEvery(), allowing legacy calls such as twig_array_some(), twig_array_every(), and twig_check_arrow_in_sandbox() to bypass sandbox callable restrictions. This issue is fixed in version 3.27.0.

Twig is a template language for PHP. Prior to 3.27.0, the column filter passes the active sandbox state as a boolean but does not forward the current Source to SandboxExtension::checkPropertyAllowed(), so SourcePolicyInterface decisions are lost and a template author can read public or magic properties not allowed by the sandbox policy. This issue is fixed in version 3.27.0.

Twig is a template language for PHP. Prior to 3.26.0, Compiler::string() does not escape single quotes when a template name from a {% use %} tag is placed inside a PHP single-quoted string literal, allowing a crafted template name to terminate the string and inject arbitrary PHP expressions into the compiled cache file. This issue is fixed in version 3.26.0.

Twig is a template language for PHP. Prior to 3.26.0, the Twig sandbox does not prevent a template from consuming CPU, memory, or wall-clock time, even under the strictest allow-list, allowing untrusted templates to cause resource exhaustion. This issue is addressed in version 3.26.0 by documenting that the sandbox does not protect against resource exhaustion.

Twig is a template language for PHP. From 3.15.0 until 3.26.0, _self.(<string>) and import-alias dynamic attribute syntax can concatenate an attacker-controlled string into a MacroReferenceExpression name without identifier validation, causing raw PHP to be emitted into the generated template source and executed at template-load time. This issue is fixed in version 3.26.0.

Twig is a template language for PHP. From 3.24.0 until 3.26.0, object-destructuring assignment compiles CoreExtension::getAttribute() with the sandbox argument hardcoded to false, disabling property and method policy checks and allowing an attacker with write access to a sandboxed Twig template to read public properties or invoke public getters on objects passed to the template engine. This issue is fixed in version 3.26.0.

Twig is a template language for PHP. Prior to 3.26.0, several filters in twig/markdown-extra and twig/cssinliner-extra are registered with is_safe => [all], causing Twig to treat plain text or HTML output as safe in HTML, JavaScript, CSS, URL, and other contexts where the output is not properly escaped. This issue is fixed in version 3.26.0.

Twig is a template language for PHP. Prior to 3.27.0, the per-template filter, tag, and function allow-list verdict is computed when a Template instance is constructed and can remain cached after sandbox state changes between renders, allowing a later sandboxed render to reuse a template that was originally checked with a different or empty policy. This issue is fixed in version 3.27.0.

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.