---
id: CVE-2025-71359
title: >-
  picklescan before 0.0.29 fails to detect malicious pickle payloads that
  utilize lib2to3.pgen2.grammar.Grammar.loads in the reduce method, allowing
  remote code execution
summary: >-
  picklescan before 0.0.29 fails to detect malicious pickle payloads that
  utilize lib2to3.pgen2.grammar.Grammar.loads in the reduce method, allowing
  remote code execution. Attackers can craft pickle files embedding dangerous
  code that evad…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N'
cwe:
  - CWE-502
published: '2026-07-04'
updated: '2026-07-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-71359'
references:
  - url: >-
      https://github.com/mmaitre314/picklescan/security/advisories/GHSA-f54q-57x4-jg88
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/picklescan-unsafe-deserialization-via-lib2to3-pgen2-grammar-grammar-loads
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00613
epssPercentile: 0.47133
ingestedAt: '2026-07-04T21:57:46.839Z'
---

## Overview

picklescan before 0.0.29 fails to detect malicious pickle payloads that utilize lib2to3.pgen2.grammar.Grammar.loads in the reduce method, allowing remote code execution. Attackers can craft pickle files embedding dangerous code that evades picklescan detection and executes during pickle.load() deserialization.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.