FKIE_CVE-2025-56005

Vulnerability from fkie_nvd - Published: 2026-01-20 19:15 - Updated: 2026-02-06 20:16
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
cve@mitre.orghttps://github.com/bohmiiidd/Undocumented-RCE-in-PLYExploit, Third Party Advisory
cve@mitre.orghttps://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005Exploit, Third Party Advisory
cve@mitre.orghttps://github.com/tom025/ply_exploit_rejectionExploit, Mitigation, Third Party Advisory
cve@mitre.orghttps://github.com/tom025/ply_exploit_rejection/issues/1
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/23/4Exploit, Mailing List
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/23/5Mailing List
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/28/5Exploit, Mailing List
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/29/1Exploit, Mailing List
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/29/2Mailing List
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/01/30/1
Impacted products
Vendor Product Version
dabeaz ply 3.11
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:dabeaz:ply:3.11:*:*:*:*:*:*:*",
              "matchCriteriaId": "278FED9B-7970-410E-B5F5-C87B229441CC",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [
    {
      "sourceIdentifier": "cve@mitre.org",
      "tags": [
        "disputed"
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "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",
  "lastModified": "2026-02-06T20:16:08.237",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-20T19:15:49.247",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/bohmiiidd/Undocumented-RCE-in-PLY"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Mitigation",
        "Third Party Advisory"
      ],
      "url": "https://github.com/tom025/ply_exploit_rejection"
    },
    {
      "source": "cve@mitre.org",
      "url": "https://github.com/tom025/ply_exploit_rejection/issues/1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/01/23/4"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/01/23/5"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/01/28/5"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/01/29/1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/01/29/2"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/01/30/1"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.