The vulnerability allows an attacker to embed a cProfile.runctx function call in the reduce method of a pickle file, which picklescan fails to detect. When such a malicious pickle is loaded via pickle.load(), arbitrary code execution occurs with the privileges of the process running the load. This flaw is classified as an unsafe serialization issue (CWE-502) and can lead to full compromise of the host system.

Picklescan is affected in all releases prior to 0.0.30. Any deployment that uses picklescan to load pickle files that may originate from untrusted sources is at risk. The issue is not limited to a specific operating system but applies wherever picklescan is installed.

The vulnerability carries a CVSS score of 7.6, indicating a high severity. No EPSS score is available, and the flaw is not listed in the CISA KEV catalog. Exploitation requires an attacker to supply or trick an application into loading a crafted pickle file containing the cProfile.runctx call. If the application processes untrusted pickle inputs, the attacker can gain arbitrary code execution on that system. The attack vector is inferred to be an adversary-controlled file or data stream.