TopVuln

Details

CVSS v3

9.8

NVD published

2026-01-20 19:15:49

EPSS

0.9% probability · 76.4th percentile — 2026-04-14

Affected versions

cpe:2.3:a:dabeaz:ply:3.11:*:*:*:*:*:*:*

Summary

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.

Remediation

Not available in our cache.

Exploit info

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 http://www.openwall.com/lists/oss-security/2026/01/23/4 http://www.openwall.com/lists/oss-security/2026/01/28/5 http://www.openwall.com/lists/oss-security/2026/01/29/1