CVE-2026-34444: Lupa has a Sandbox escape and RCE due to incomplete attribute_filter enforcement in getattr / setattr

Lupa integrates the runtimes of Lua or LuaJIT2 into CPython. In 2.6 and earlier, attribute_filter is not consistently applied when attributes are accessed through built-in functions like getattr and setattr. This allows an attacker to bypass the intended restrictions and eventually achieve arbitrary code execution.