CVE-2025-56005
CVE-2025-56005
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
n/a · n/apublic PoCs found — 2
githubgithub.com/tom025/ply_exploit_rejection★ 0githubgithub.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005★ 0⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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https://github.com/bohmiiidd/Undocumented-RCE-in-PLYhttps://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005https://github.com/tom025/ply_exploit_rejectionhttps://github.com/tom025/ply_exploit_rejection/issues/1http://www.openwall.com/lists/oss-security/2026/01/23/4http://www.openwall.com/lists/oss-security/2026/01/23/5http://www.openwall.com/lists/oss-security/2026/01/28/5http://www.openwall.com/lists/oss-security/2026/01/29/1http://www.openwall.com/lists/oss-security/2026/01/29/2http://www.openwall.com/lists/oss-security/2026/01/30/1