### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
Update twig/twig to 3.26.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanTwig: Arbitrary PHP code execution via `_self.(<string>)` macro-reference compilation affects twig/twig (composer). Severity is high. ### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
AI coding agents often install or upgrade packages automatically in composer. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| twig/twigcomposer | >=3.15.0,<3.26.0 | 3.26.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate twig/twig to 3.26.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanTwig: Arbitrary PHP code execution via `_self.(<string>)` macro-reference compilation affects twig/twig (composer). Severity is high. ### Description The `obj.(expr)` dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated `attribute()` function) lets the attribute be an arbitrary expression. When the receiver is `_self` (or any `{% import %}` alias) and the parenthesised expression is a string literal, `DotExpressionParser` short-circuits to the macro-call path and concatenates the attacker-controlled string into a `MacroReferenceExpression` name with no identifier validation. `MacroReferenceExpression::compile()` then emits that name raw into the generated PHP source. An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before `checkSecurity()` is ever called. This is a complete bypass of `SandboxExtension`, including a globally-enabled sandbox with an empty `SecurityPolicy` allowlist. ### Resolution The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through `MacroReferenceExpression`, and the macro-reference compiler emits the name through a properly escaped path. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
AI coding agents often install or upgrade packages automatically in composer. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| twig/twigcomposer | >=3.15.0,<3.26.0 | 3.26.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard