CVE 9.8 CRITICAL

CVE-2025-56005_CVE-2025-56005

January 20, 2026 invoker category_cve

9.8 / 10

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Description

An undocumented and unsafe feature in the PLY (Python Lex-Yacc) library 3.11 allows Remote Code Execution (RCE) via the `picklefile` parameter in the `yacc()` function. This parameter accepts a `.pkl` file that is deserialized with `pickle.load()` without validation. Because `pickle` allows execution of embedded code via `__reduce__()`, an attacker can achieve code execution by passing a malicious pickle file. The parameter is not mentioned in official documentation or the GitHub repository, yet it is active in the PyPI version. This introduces a stealthy backdoor and persistence risk.

AI Analysis

Undocumented and unsafe feature in PLY library allows Remote Code Execution (RCE) via picklefile parameter

Basic Information

ID CVE-2025-56005

Source mitre

Published Jan 20, 2026 at 00:00

Modified Jan 20, 2026 at 18:49

Affected Product

Vendor PLY Project

Product PLY

Version 3.11

Affected Versions n/a n/a n/a

CWE Classification

CWE-502

AI Assessment

AI Score 9.8 / 10

AI Severity Critical

Vendor PLY Project

Product PLY

Version 3.11

References

github.com /bohmiiidd/Undocumented-RCE-in-PLY

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