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PLY Python library allows malicious files to run code
OESA-2026-1594
Summary
A security update is available for the PLY Python library. An attacker could potentially exploit a hidden feature to run malicious code on a system. To stay safe, update the library to the latest version.
What to do
- Update python-ply to version 3.11-4.oe2203sp4.
Affected software
| Vendor | Product | Affected versions | Fix available |
|---|---|---|---|
| – | python-ply | <= 3.11-4.oe2203sp4 | 3.11-4.oe2203sp4 |
Original title
python-ply security update
Original description
/ply/
/ply--*.egg-info/
Security Fix(es):
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.(CVE-2025-56005)
/ply--*.egg-info/
Security Fix(es):
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.(CVE-2025-56005)
- https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA... Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2025-56005 Vendor Advisory
Published: 15 Mar 2026 · Updated: 15 Mar 2026 · First seen: 15 Mar 2026