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

Description This is a residual bypass of CVE-2026-47732 / GHSA-pr2w-4gpj-cpq4 left after the initial fix for unguarded toString calls. It covers two related coercion points that were not caught by the original patch. Traversable in join and replace filters. SandboxExtension::ensureToStringAllowed...

GHSA-5V5V-WW74-355V Twig: Sandbox `__toString()` policy bypass via dynamic mapping keys

Description This is a residual bypass of CVE-2026-47732 / GHSA-pr2w-4gpj-cpq4 left after the initial fix for unguarded toString calls. In 3.26.0 the sandbox visitor was extended to wrap every child node that its parent will string-coerce at runtime with CheckToStringNode, gated by the new...

Twig: Sandbox: multiple `__toString()` policy bypasses via unguarded string coercion points

Description SandboxNodeVisitor enforces SecurityPolicy::checkMethodAllowed for implicit toString calls by wrapping selected AST nodes in CheckToStringNode. The set of wrapped nodes is incomplete, and several Twig language constructs still trigger PHP string coercion on a Stringable operand withou...