CVE-2026-53753 Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API

Crawl4AI is an open-source LLM friendly web crawler & scraper. Prior to 0.8.7, the safeevalexpression function in the computed fields feature uses an AST validator that only blocks attributes starting with underscore. Python generator and frame object attributes giframe, fback, fbuiltins do NOT...