The vulnerability arises from unsafe deserialization of Python pickle data in picklescan versions prior to 0.0.35, allowing attackers to trigger the loading of arbitrary files by chaining io.FileIO with urllib.request.urlopen. This can result in sensitive data such as /etc/passwd being read and exfiltrated to an external server. The weakness is a classic path traversal and insecure deserialization flaw identified as CWE-22.

The flaw affects the picklescan application developed by mmaitre314, any installation running version 0.0.34 or earlier, regardless of deployment environment.

The CVSS score of 8.7 marks this as a high‑severity issue, while the EPSS score is less than 1% indicating a low but nonzero likelihood of exploitation. The vulnerability can be triggered by unauthenticated attackers who can supply malicious pickle payloads to an exposed endpoint. If the application is reachable from untrusted networks, the attacker can read any file accessible to the process and transmit it externally, thereby compromising confidentiality. The flaw is not currently listed in the CISA KEV catalog.