{"id":"PYSEC-2026-1783","summary":"Picklescan is vulnerable to RCE through missing detection when calling numpy.f2py.crackfortran._eval_length","details":"### Summary\n\nPicklescan uses the `numpy.f2py.crackfortran._eval_length` function (a NumPy F2PY helper) to execute arbitrary Python code during unpickling.\n\n### Details\n\nPicklescan fails to detect a malicious pickle that uses the gadget `numpy.f2py.crackfortran._eval_length` in `__reduce__`, allowing arbitrary command execution when the pickle is loaded. A crafted object returns this function plus attacker‑controlled arguments; the scan reports the file as safe, but pickle.load() triggers execution.\n\n### PoC\n```python\nclass PoC:\n    def __reduce__(self):\n        from numpy.f2py.crackfortran import _eval_length\n        return _eval_length, (\"__import__('os').system('whoami')\", None)\n```\n\n### Impact\n\n- Arbitrary code execution on the victim machine once they load the “scanned as safe” pickle / model file.\n- Affects any workflow relying on Picklescan to vet untrusted pickle / PyTorch artifacts.\n- Enables supply‑chain poisoning of shared model files.\n\n### Credits\n- [ac0d3r](https://github.com/ac0d3r)\n- [Tong Liu](https://lyutoon.github.io), Institute of information engineering, CAS","aliases":["CVE-2025-71339","GHSA-6556-fwc2-fg2p"],"modified":"2026-07-07T17:48:02.171297685Z","published":"2026-07-07T16:03:14.498992Z","references":[{"type":"WEB","url":"https://github.com/mmaitre314/picklescan/security/advisories/GHSA-6556-fwc2-fg2p"},{"type":"WEB","url":"https://github.com/mmaitre314/picklescan/pull/53"},{"type":"WEB","url":"https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab"},{"type":"PACKAGE","url":"https://github.com/mmaitre314/picklescan"},{"type":"WEB","url":"https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33"},{"type":"PACKAGE","url":"https://pypi.org/project/picklescan"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-6556-fwc2-fg2p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-71339"}],"affected":[{"package":{"name":"picklescan","ecosystem":"PyPI","purl":"pkg:pypi/picklescan"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.0.33"}]}],"versions":["0.0.1","0.0.10","0.0.11","0.0.12","0.0.13","0.0.14","0.0.15","0.0.16","0.0.17","0.0.18","0.0.19","0.0.2","0.0.20","0.0.21","0.0.22","0.0.23","0.0.24","0.0.25","0.0.26","0.0.27","0.0.28","0.0.29","0.0.3","0.0.30","0.0.31","0.0.32","0.0.4","0.0.5","0.0.6","0.0.7","0.0.8","0.0.9"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/picklescan/PYSEC-2026-1783.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P"}]}