Security Updates for Microsoft Exchange Server (October 2026)

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

include('compat.inc');

if (description)
{
  script_id(365663);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/15");

  script_cve_id(
    "CVE-2026-70279",
    "CVE-2026-70571",
    "CVE-2026-77910",
    "CVE-2026-87692",
    "CVE-2026-87695",
    "CVE-2026-87696"
  );
  script_xref(name:"MSKB", value:"5128895");
  script_xref(name:"MSKB", value:"5128896");
  script_xref(name:"MSKB", value:"5128897");
  script_xref(name:"MSKB", value:"5128898");
  script_xref(name:"MSFT", value:"MS26-5128895");
  script_xref(name:"MSFT", value:"MS26-5128896");
  script_xref(name:"MSFT", value:"MS26-5128897");
  script_xref(name:"MSFT", value:"MS26-5128898");

  script_name(english:"Security Updates for Microsoft Exchange Server (October 2026)");

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

  - Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange
    Server allows an unauthorized attacker to perform spoofing over a network. (CVE-2026-70279)

  - Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code
    over a network. (CVE-2026-70571)

  - Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges
    over a network. (CVE-2026-77910)

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/5128895");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5128896");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5128897");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5128898");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:
  -KB5128895
  -KB5128896
  -KB5128897
  -KB5128898");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N");
  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:C/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-70279");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(79, 121, 347, 502, 829, 863);

  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:"2026/10/14");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server:2016");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server:2019");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server:subscription_edition");
  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("ms_bulletin_checks_possible.nasl", "microsoft_exchange_installed.nbin");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('vcf.inc');
include('vcf_extras_microsoft.inc');

var app_info = vcf::microsoft::exchange::get_app_info();

var constraints = [
  { 'fixed_version' : '15.1.2507.77', 'product' : '2016', 'cu' : 23, 'unsupported_cu' : 22, 'kb' : '5128898' },
  { 'fixed_version' : '15.2.1544.50', 'product' : '2019', 'cu' : 14, 'unsupported_cu' : 13, 'kb' : '5128897' },
  { 'fixed_version' : '15.2.1748.55', 'product' : '2019', 'cu' : 15, 'unsupported_cu' : 13, 'kb' : '5128896' },
  { 'fixed_version' : '15.2.2562.56', 'product' : 'Subscription Edition', 'cu' : 0, 'kb' : '5128895' }
];

vcf::microsoft::exchange::check_version_and_report(
  app_info:app_info,
  bulletin:'MS26-10',
  constraints:constraints,
  severity:SECURITY_HOLE
);