PYSEC-2026-3568 Flyto2 Core: Arbitrary file write via image.download (and other file-writing modules)

Summary image.download fetches a URL and writes the response to disk. It does not use the central path guard validatepathwithenvconfig, which confines writes to FLYTOSANDBOXDIR; instead it confines the output to outputdir, but outputdir is itself a caller parameter. Since the attacker sets both t...