System Capybara: Tracking Capabilities for Separation and Freshness (Extended Version)

This collection of recent PL/security papers contains several items with direct security relevance. Key points: (1) “Toward Inferring Accurate Context-free Grammars…” (Xvada) reports discovery of a vulnerability in the widely used Python Liquid templating engine and additional bugs found via grammar-guided fuzzing; fixes were applied by the maintainers. (2) “The LLMbda Calculus” gives an executable, machine-checked calculus and interpreter that enforces provenance-based defenses against prompt-injection (dynamic information-flow labels, reclassification) and proves termination-insensitive non‑