A deserialization flaw in picklescan allows attackers to craft malicious pickle files that use the numpy.f2py.crackfortran.param_eval function within reduce methods. When such a pickle is deserialized, the embedded code executes without detection, giving the attacker arbitrary command execution on the host. This is a classic pickling vulnerability (CWE-502) that threatens confidentiality, integrity, and availability of the system processing the payload.

The vulnerability affects the picklescan tool, specifically versions before 0.0.33. Any application that incorporates picklescan to load or analyze untrusted pickle data is potentially exposed, including third‑party software that relies on picklescan for data handling or threat detection.

The base CVSS score of 7.6 indicates high severity, while the EPSS score of less than 1% suggests that exploitation attempts are infrequent at present. The issue is not listed in the CISA KEV catalog. Attackers can achieve remote code execution by supplying a crafted pickle file that triggers the undiscovered numpy.f2py.crackfortran.param_eval path during deserialization. Because the flaw arises in a deserialization library, successful exploitation requires that an application actually deserialize external pickle data, but the impact of execution would be system wide if privileges are elevated.