GHSA-6XH2-93P9-VQH4 oban_web: Unbounded range expansion in cron describe causes memory exhaustion

Summary obanweb 2.12.0 introduced a cron expression parser that expands --separated ranges without validating the endpoints. An attacker with access to schedule cron jobs can submit a malicious expression; when any user with dashboard access views the cron job list, Oban.Web.CronExpr.describe/1 i...