Security Updates for Microsoft SharePoint Server 2016 (January 2026)

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

include('compat.inc');

if (description)
{
  script_id(283468);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/18");

  script_cve_id(
    "CVE-2026-20943",
    "CVE-2026-20947",
    "CVE-2026-20948",
    "CVE-2026-20963",
    "CVE-2026-20951",
    "CVE-2026-20958",
    "CVE-2026-20959"
  );
  script_xref(name:"MSKB", value:"5002828");
  script_xref(name:"MSFT", value:"MS26-5002828");
  script_xref(name:"IAVA", value:"2026-A-0043-S");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2026/03/21");

  script_name(english:"Security Updates for Microsoft SharePoint Server 2016 (January 2026)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft SharePoint Server 2016 installation on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft SharePoint Server 2016 installation on the
remote host is missing security updates. It is, therefore,
affected by multiple vulnerabilities:

  - A remote code execution vulnerability. An attacker can
    exploit this to bypass authentication and execute
    unauthorized arbitrary commands. (CVE-2026-20947,
    CVE-2026-20948, CVE-2026-62551, CVE-2026-62563)

  - A session spoofing vulnerability exists. An attacker can
    exploit this to perform actions with the privileges of
    another user. (CVE-2026-20958)

  - A information disclosure vulnerability exists. An 
    authorized attacker could use this to disclose 
    information over a network (CVE-2026-20959)

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://support.microsoft.com/en-us/help/5002828");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20947");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20948");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20951");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20958");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20959");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released security updates to address this issue.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-20947");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-20959");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/01/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/01/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/01/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:sharepoint_server:2016");
  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("microsoft_sharepoint_installed.nbin", "smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('vcf_extras_microsoft.inc');

var app_info = vcf::microsoft::sharepoint::get_app_info();
var kb_checks = 
[
  {
    'product'      : '2016',
    'edition'      : 'Server',
    'kb'           : '5002828',
    'path'         : app_info.path,
    'version'      : '16.0.5535.1000',
    'append'       : 'webservices\\conversionservices',
    'file'         : 'sword.dll',
    'product_name' : 'Microsoft Sharepoint Enterprise Server 2016 SP1' 
  }
];
vcf::microsoft::sharepoint::check_version_and_report
(
  app_info:app_info, 
  bulletin:'MS26-01',
  constraints:kb_checks, 
  severity:SECURITY_HOLE
);