In Trail of Bits fickling through 0.1.12, the processimport() method in fickle.py adds an imported name to the likelysafeimports set…

In Trail of Bits fickling through 0.1.12, the processimport() method in fickle.py adds an imported name to the likelysafeimports set whenever the source module is present in sys.stdlibmodulenames and the name is absent from the UNSAFEIMPORTS denylist, without inspecting what the name resolves to or how it behaves. The OvertlyBadEvals analysis pass in analysis.py then unconditionally skips any call whose function name appears in likelysafeimports, including calls that would otherwise be flagged as overtly dangerous. As a result, any callable reachable through a non-blocked standard library module inherits module-level trust regardless of its own behavior, and checksafety() returns LIKELYSAFE with zero findings for pickle payloads that reach code execution or file write through such callables. Demonstrated primitives: dataclasses.createfn, which passes an attacker-controlled function body to exec() and yields arbitrary code execution on Python 3.7 through 3.12 (the internal createfn function was removed in Python 3.13); mailcap.findmatch, which internally calls os.system() on a test command taken from an attacker-controlled caps dictionary, yielding arbitrary code execution on…

curl https://cve.zerocrew.in/api/cve/CVE-2026-16760