CVE-2026-53873: picklescan - Arbitrary Code Execution via profile.run() Blocklist Bypass

Synopsis

This is an arbitrary code execution vulnerability in picklescan, a Python library used to detect malicious pickle files. The flaw is reachable over the network with no authentication required, because any system that accepts and scans pickle files from untrusted sources is exposed. An attacker crafts a malicious pickle file that calls profile.run() to execute arbitrary Python code, while picklescan reports zero security issues, giving no indication that the payload ran. A patched-image rebuild at version 1.0.4 is available on HarborGuard for affected environments.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must be able to deliver a crafted pickle file to a service that invokes picklescan over the network; any internet-exposed or internally networked file-intake endpoint that calls picklescan is in scope.

• AuthenticationNot required

  No credentials or account are needed; the attacker only needs to submit a file to a picklescan-scanning endpoint, which typically accepts unauthenticated input.

• Victim interactionNot required

  No user action is required; exploitation occurs automatically when picklescan processes the malicious pickle file.

• Attack complexityDetail

  The exploit is reliable and condition-free; crafting a pickle payload that calls profile.run() requires no race conditions, memory layout knowledge, or special environmental prerequisites.

Blast Radius

• The attacker executes arbitrary Python code in the process running picklescan, gaining full control of that process and its runtime environment.
• Any secrets, credentials, or tokens accessible to the scanning process (such as environment variables or mounted files) are readable by the attacker.
• The attacker can modify or delete files and data accessible to the scanning process, including scan results and downstream pipeline artifacts.
• The scanning service itself can be crashed or repurposed, disabling the security gate that picklescan is meant to provide.