Microsoft PowerShell 7.4.x < 7.4.21 / 7.5.x < 7.5.12 / 7.6.x < 7.6.7 Multiple Vulnerabilities (October 2026)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(366463);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/19");

  script_cve_id("CVE-2026-96251", "CVE-2026-96303");
  script_xref(name:"IAVA", value:"2026-A-1131");

  script_name(english:"Microsoft PowerShell 7.4.x < 7.4.21 / 7.5.x < 7.5.12 / 7.6.x < 7.6.7 Multiple Vulnerabilities (October 2026)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft PowerShell install on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of Microsoft PowerShell installed on the remote host is 7.4.x prior to 7.4.21, 7.5.x prior to 7.5.12, or
7.6.x prior to 7.6.7. It is, therefore, affected by multiple vulnerabilities:

  - Reliance on untrusted inputs in a security decision in Microsoft PowerShell allows an unauthorized attacker to
    execute code over a network. (CVE-2026-96251)

  - Improperly implemented security check for standard in Microsoft PowerShell allows an unauthorized attacker to
    bypass a security feature over a network. (CVE-2026-96303)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96251");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96303");
  # https://github.com/PowerShell/Announcements/blob/main/pwsh/2026/10/CVE-2026-96251.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?80371a08");
  # https://github.com/PowerShell/Announcements/blob/main/pwsh/2026/10/CVE-2026-96303.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?69bce79a");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Microsoft PowerShell version 7.4.21, 7.5.12, 7.6.7, or later.");
  script_set_attribute(attribute:"agent", value:"windows");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-96251");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:powershell");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("smb_hotfixes.nasl", "wmi_enum_windows_app_store.nbin");
  script_require_keys("SMB/Registry/Enumerated", "WMI/Windows App Store/Enumerated", "installed_sw/Microsoft.PowerShell");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'checks': [
    {
      'product': {'name': 'Microsoft.PowerShell', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '7.4.0', 'fixed_version': '7.4.21'},
        {'min_version': '7.5.0', 'fixed_version': '7.5.12'},
        {'min_version': '7.6.0', 'fixed_version': '7.6.7'}
      ]
    }
  ]
};

var result = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_HOLE);
vdf::handle_check_and_report_errors(vdf_result:result);