CVE-2025-56005 - PLY Python Lex-Yacc Remote Code Execution (RCE) via Unvalidated Pickle File

CVE ID : CVE-2025-56005 Published : Jan. 20, 2026, 7:15 p.m. | 1 hour, 40 minutes ago 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. Severity: 9.8 | CRITICAL Visit the link for more details, such as CVSS details, affected products, timeline, and more...