Security Updates for Microsoft Office Products C2R (February 2026)

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

include('compat.inc');

if (description)
{
  script_id(298977);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/13");

  script_cve_id("CVE-2026-21509");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2026/02/16");

  script_name(english:"Security Updates for Microsoft Office Products C2R (February 2026)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft Office Products are affected by a security feature bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office Products are missing security updates. It is, therefore, affected by a vulnerability:

  - A security feature bypass vulnerability. Reliance on untrusted inputs in a security decision in Microsoft
    Office allows an unauthorized attacker to bypass a security feature locally. (CVE-2026-21509)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5931548c");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released patches to address these issues.

For Office 365, Office 2016 C2R, or Office 2019, 2021 or 2024,
ensure automatic updates are enabled or open any office app
and manually perform an update.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-21509");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/01/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/02/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/13");

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

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

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

  script_dependencies("office_installed.nasl", "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_office.inc');

var bulletin = 'MS26-02';

var app_info = vcf::microsoft::office::get_app_info(app:'Microsoft Office');

var constraints = [
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.19628.20204','channel':'Current'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.19530.20226','channel':'Enterprise Deferred','channel_version':'2512'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.19426.20294','channel':'Enterprise Deferred','channel_version':'2511'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.19328.20306','channel':'Enterprise Deferred'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.19127.20532','channel':'Deferred','channel_version':'2508'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.18526.20714','channel':'Deferred','channel_version':'2502'},
  {'product':'Microsoft Office 365','file':'graph.exe','fixed_version':'16.0.17928.20776','channel':'Deferred'},
  {'product':'Microsoft Office 2024','file':'graph.exe','fixed_version':'16.0.19628.20204','channel':'2024 Retail'},
  {'product':'Microsoft Office 2021','file':'graph.exe','fixed_version':'16.0.19628.20204','channel':'2021 Retail'},
  {'product':'Microsoft Office 2024','file':'graph.exe','fixed_version':'16.0.17932.20670','channel':'LTSC 2024'},
  {'product':'Microsoft Office 2021','file':'graph.exe','fixed_version':'16.0.14334.20522','channel':'LTSC 2021'},
  {'product':'Microsoft Office 2019','file':'graph.exe','fixed_version':'16.0.10417.20097','channel':'2019 Volume'}
];

vcf::microsoft::office::check_version_and_report(
  app_info:app_info,
  constraints:constraints,
  severity:SECURITY_HOLE,
  bulletin:bulletin,
  subproduct:'Office'
);