Linux Distros Unpatched Vulnerability : CVE-2025-56005

critical Nessus Plugin ID 294837

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Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- 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)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Critical

ID: 294837

File Name: unpatched_CVE_2025_56005.nasl

Version: 1.5

Type: local

Agent: unix

Family: Misc.

Published: 1/21/2026

Updated: 2/9/2026

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2025-56005

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:U/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:python39-ply, p-cpe:/a:centos:centos:keylime-verifier, p-cpe:/a:centos:centos:keylime-registrar, p-cpe:/a:redhat:enterprise_linux:keylime-registrar, cpe:/o:debian:debian_linux:14.0, cpe:/o:debian:debian_linux:11.0, p-cpe:/a:redhat:enterprise_linux:nginx-122, p-cpe:/a:redhat:enterprise_linux:support-tools, p-cpe:/a:redhat:enterprise_linux:mariadb-103, p-cpe:/a:centos:centos:postgresql-15, cpe:/o:centos:centos:8, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:redhat:enterprise_linux:python-ply, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:redhat:enterprise_linux:keylime-verifier, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:centos:centos:nginx-122, cpe:/o:centos:centos:7, p-cpe:/a:centos:centos:python38-ply, p-cpe:/a:centos:centos:httpd-24, p-cpe:/a:centos:centos:mysql-80, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:centos:centos:mariadb-1011, p-cpe:/a:centos:centos:support-tools, p-cpe:/a:centos:centos:python-ply, p-cpe:/a:redhat:enterprise_linux:nginx-124, cpe:/o:canonical:ubuntu_linux:25.10, p-cpe:/a:centos:centos:postgresql-16, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:redhat:enterprise_linux:postgresql-15, p-cpe:/a:centos:centos:varnish-6, p-cpe:/a:redhat:enterprise_linux:mariadb-105, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:centos:centos:python3-ply, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:httpd-24, p-cpe:/a:redhat:enterprise_linux:postgresql-16, p-cpe:/a:redhat:enterprise_linux:mariadb-1011, p-cpe:/a:centos:centos:nginx-124, p-cpe:/a:redhat:enterprise_linux:varnish-6, p-cpe:/a:centos:centos:postgresql-12, p-cpe:/a:redhat:enterprise_linux:mysql-80, p-cpe:/a:centos:centos:mariadb-105, p-cpe:/a:redhat:enterprise_linux:python38-ply, p-cpe:/a:centos:centos:python39-ply, p-cpe:/a:centos:centos:postgresql-13, p-cpe:/a:redhat:enterprise_linux:postgresql-12, p-cpe:/a:redhat:enterprise_linux:postgresql-13, p-cpe:/a:redhat:enterprise_linux:python3-ply, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:debian:debian_linux:12.0, p-cpe:/a:debian:debian_linux:ply, p-cpe:/a:canonical:ubuntu_linux:ply, p-cpe:/a:centos:centos:mariadb-103

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 1/20/2026

Reference Information

CVE: CVE-2025-56005

Detections

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