CVE-2026-44265: Elo backends have code injection via unvalidated emission of programmatic AST fields

Elo’s programmatic AST API accepts arbitrary values in many node fields without runtime type or syntax validation. Each backend’s emit stage interpolates those values straight into the generated source with no escape pass. An integrator that populates the AST from JSON-deserialised input, plugin output, or any other untyped source therefore exposes a code-injection primitive that flows through to the emitted JavaScript, Ruby, Python, or SQL.

The same pattern was previously addressed in 0.9.7 (2026-01-27), which patched the date/datetime/duration literal emitters via JSON.stringify() after a report by naoyashiga. This advisory generalises that fix to the remaining AST surface — at least 23 emission sites across six node-field categories and four backends.