GHSA-QC6M-PWR3-G72P

Vulnerability from github – Published: 2026-01-20 21:31 – Updated: 2026-06-30 03:35
VLAI
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.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2025-56005"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-20T19:15:49Z",
    "severity": "CRITICAL"
  },
  "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.",
  "id": "GHSA-qc6m-pwr3-g72p",
  "modified": "2026-06-30T03:35:26Z",
  "published": "2026-01-20T21:31:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-56005"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tom025/ply_exploit_rejection/issues/1"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2025-56005"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2431308"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bohmiiidd/Undocumented-RCE-in-PLY"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tom025/ply_exploit_rejection"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-56005.json"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/23/4"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/23/5"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/28/5"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/29/1"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/29/2"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/30/1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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