---
id: CVE-2025-71343
title: >-
  picklescan before 0.0.30 fails to detect malicious pickle files that exploit
  lib2to3.pgen2.pgen.ParserGenerator.make_label function in the reduce method
summary: >-
  picklescan before 0.0.30 fails to detect malicious pickle files that exploit
  lib2to3.pgen2.pgen.ParserGenerator.make_label function in the reduce method.
  Attackers can craft malicious pickle files with embedded code that evades
  detection…
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-2025-71343'
references:
  - url: >-
      https://github.com/mmaitre314/picklescan/security/advisories/GHSA-p9w7-82w4-7q8m
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-lib2to3-pgen2-pgen-parsergenerator-make-label-detection-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00431
epssPercentile: 0.34752
ingestedAt: '2026-07-04T21:57:46.827Z'
---

## Overview

picklescan before 0.0.30 fails to detect malicious pickle files that exploit lib2to3.pgen2.pgen.ParserGenerator.make_label function in the reduce method. Attackers can craft malicious pickle files with embedded code that evades detection but executes arbitrary commands when pickle.load() is called.

## Remediation

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