KB5075941: Windows 11 version 23H2 Security Update (February 2026)

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

#
# The descriptive text and package checks in this plugin were
# extracted from the Microsoft Security Updates API. The text
# itself is copyright (C) Microsoft Corporation.
##

include('compat.inc');

if (description)
{
  script_id(298554);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/30");

  script_cve_id(
    "CVE-2026-20846",
    "CVE-2026-21222",
    "CVE-2026-21231",
    "CVE-2026-21232",
    "CVE-2026-21234",
    "CVE-2026-21235",
    "CVE-2026-21236",
    "CVE-2026-21237",
    "CVE-2026-21238",
    "CVE-2026-21239",
    "CVE-2026-21240",
    "CVE-2026-21241",
    "CVE-2026-21242",
    "CVE-2026-21244",
    "CVE-2026-21246",
    "CVE-2026-21247",
    "CVE-2026-21248",
    "CVE-2026-21249",
    "CVE-2026-21253",
    "CVE-2026-21255",
    "CVE-2026-21508",
    "CVE-2026-21510",
    "CVE-2026-21513",
    "CVE-2026-21519",
    "CVE-2026-21525",
    "CVE-2026-21533"
  );
  script_xref(name:"MSKB", value:"5075941");
  script_xref(name:"MSFT", value:"MS26-5075941");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2026/03/03");
  script_xref(name:"IAVA", value:"2026-A-0112-S");
  script_xref(name:"IAVA", value:"2026-A-0111-S");

  script_name(english:"KB5075941: Windows 11 version 23H2 Security Update (February 2026)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote Windows host is missing security update 5075941. It is, therefore, affected by multiple vulnerabilities

  - Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security
    feature over a network. (CVE-2026-21513)

  - Access of resource using incompatible type ('type confusion') in Desktop Window Manager allows an
    authorized attacker to elevate privileges locally. (CVE-2026-21519)

  - Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.
    (CVE-2026-21244, CVE-2026-21248)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5075941");
  script_set_attribute(attribute:"solution", value:
"Apply Security Update 5075941");
  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:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-21513");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-21508");

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

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

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows_11_23h2");
  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_check_rollup.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('smb_func.inc');
include('smb_hotfixes.inc');
include('smb_hotfixes_fcheck.inc');
include('smb_reg_query.inc');

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

var bulletin = 'MS26-02';
var kbs = make_list(
  '5075941'
);

if (get_kb_item('Host/patch_management_checks')) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_HOLE);

get_kb_item_or_exit('SMB/Registry/Enumerated');
get_kb_item_or_exit('SMB/WindowsVersion', exit_code:1);

if (hotfix_check_sp_range(win10:'0') <= 0) audit(AUDIT_OS_SP_NOT_VULN);

var share = hotfix_get_systemdrive(as_share:TRUE, exit_on_fail:TRUE);
if (!is_accessible_share(share:share)) audit(AUDIT_SHARE_FAIL, share);

if (
  smb_check_rollup(os:'10',
                   os_build:22631,
                   rollup_date:'02_2026',
                   bulletin:bulletin,
                   rollup_kb_list:[5075941])
)
{
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_hole();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, hotfix_get_audit_report());
}