{
  "affected": [
    {
      "database_specific": {
        "unresolved_ranges": [
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "3.11"
              }
            ]
          }
        ]
      }
    }
  ],
  "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.",
  "id": "CVE-2025-56005",
  "modified": "2026-03-15T21:45:13.038696804Z",
  "published": "2026-01-20T19:15:49.247Z",
  "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"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}