{"id":"CVE-2025-56005","details":"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.","modified":"2026-04-16T04:39:40.073517195Z","published":"2026-01-20T19:15:49.247Z","related":["openSUSE-SU-2026:10418-1"],"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/01/30/1"},{"type":"REPORT","url":"https://github.com/tom025/ply_exploit_rejection/issues/1"},{"type":"PACKAGE","url":"https://github.com/tom025/ply_exploit_rejection"},{"type":"ARTICLE","url":"http://www.openwall.com/lists/oss-security/2026/01/23/5"},{"type":"ARTICLE","url":"http://www.openwall.com/lists/oss-security/2026/01/29/2"},{"type":"EVIDENCE","url":"https://github.com/bohmiiidd/Undocumented-RCE-in-PLY"},{"type":"EVIDENCE","url":"http://www.openwall.com/lists/oss-security/2026/01/29/1"},{"type":"EVIDENCE","url":"https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005"},{"type":"EVIDENCE","url":"http://www.openwall.com/lists/oss-security/2026/01/23/4"},{"type":"EVIDENCE","url":"http://www.openwall.com/lists/oss-security/2026/01/28/5"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-56005.json","unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"3.11"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}