CVE-2025-56005

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-114724 Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 contains an object injection… CWE-502
• CVE-2026-112081 A vulnerability was determined in hankcs HanLP up to 2.1.0-beta.64. CWE-502
• CVE-2026-96745 Deserialization of untrusted data in the command monitoring support of the MongoDB PHP… CWE-502
• CVE-2026-62107 Unauthenticated PHP Object Injection in Masteriyo - LMS <= 3.4.0 versions. CWE-502
• CVE-2026-62103 Unauthenticated PHP Object Injection in Everest Forms <= 3.6.0 versions. CWE-502
• CVE-2026-62105 Unauthenticated PHP Object Injection in ThemeREX Addons < 2.45.0 versions. CWE-502
• CVE-2026-73699 FileRun before 2026.3.0 contains a PHP object injection vulnerability that allows… CWE-502
• CVE-2026-82925 The Site Reviews WordPress plugin before 8.3.0 does not prevent request data from being… CWE-502