CVE-2025-56005

Critical CVSS: 9.8

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. NOTE: A third-party states that this vulnerability should be rejected because the proof of concept does not demonstrate arbitrary code execution and fails to complete successfully.

Vendor

Dabeaz

Product

Ply

CWE

CWE-502

Yayın Tarihi

2026-01-20 19:15:49

Güncelleme

2026-02-06 20:16:08

Source Identifier

cve@mitre.org

KEV Date Added

Kategoriler

CWE-502 Ply CRITICAL Dabeaz 2026

Referanslar

https://github.com/bohmiiidd/Undocumented-RCE-in-PLY https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005 https://github.com/tom025/ply_exploit_rejection https://github.com/tom025/ply_exploit_rejection/issues/1 http://www.openwall.com/lists/oss-security/2026/01/23/4 http://www.openwall.com/lists/oss-security/2026/01/23/5 http://www.openwall.com/lists/oss-security/2026/01/28/5 http://www.openwall.com/lists/oss-security/2026/01/29/1 http://www.openwall.com/lists/oss-security/2026/01/29/2 http://www.openwall.com/lists/oss-security/2026/01/30/1