Security Update for Microsoft .NET Core (August 2026)

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

include('compat.inc');

if (description)
{
  script_id(334610);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/11");

  script_cve_id(
    "CVE-2026-58641",
    "CVE-2026-62871",
    "CVE-2026-62886",
    "CVE-2026-62897",
    "CVE-2026-62898",
    "CVE-2026-62899",
    "CVE-2026-62900",
    "CVE-2026-62901",
    "CVE-2026-62902",
    "CVE-2026-62909",
    "CVE-2026-70354"
  );

  script_name(english:"Security Update for Microsoft .NET Core (August 2026)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft .NET Core installations on the remote host are affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft .NET Core installations on the remote host are missing a security update. It is, therefore, affected by
multiple vulnerabilities as referenced in the vendor advisory.

  - .NET Elevation of Privilege Vulnerability (CVE-2026-58641, CVE-2026-62871, CVE-2026-62886, CVE-2026-62909)

  - .NET Security Feature Bypass Vulnerability (CVE-2026-62899)

  - .NET Information Disclosure Vulnerability (CVE-2026-62900, CVE-2026-62902)

  - .NET Denial of Service Vulnerability (CVE-2026-62901)

  - .NET Core Remote Code Execution Vulnerability (CVE-2026-70354)

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://github.com/dotnet/announcements/issues/426");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/427");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/428");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/429");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/430");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/431");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/432");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/433");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/434");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/435");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/436");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5122104");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5122105");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/help/5122106");
  script_set_attribute(attribute:"see_also", value:"https://dotnet.microsoft.com/download/dotnet/8.0");
  # https://github.com/dotnet/core/blob/main/release-notes/8.0/8.0.30/8.0.30.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e41c02df");
  script_set_attribute(attribute:"see_also", value:"https://dotnet.microsoft.com/download/dotnet/9.0");
  # https://github.com/dotnet/core/blob/master/release-notes/9.0/9.0.19/9.0.19.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?61681f70");
  script_set_attribute(attribute:"see_also", value:"https://dotnet.microsoft.com/download/dotnet/10.0");
  # https://github.com/dotnet/core/blob/main/release-notes/10.0/10.0.11/10.0.11.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9f457d65");
  script_set_attribute(attribute:"solution", value:
"Update .NET Core, remove vulnerable packages and refer to vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-62902");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-70354");

  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:"2026/08/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:.net_core");
  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("microsoft_dotnet_core_win.nbin");
  script_require_keys("installed_sw/.NET Core Windows");

  exit(0);
}
include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'requires': [{'scope': 'target', 'match': {'os': 'windows'}}],
  'checks': [{
    'product': {'name': '.NET Core Windows', 'type': 'app'},
    'check_algorithm': 'default',
    'constraints': [{
      'min_version': '8',
      'fixed_version': '8.0.30'
    },{
      'min_version': '9',
      'fixed_version': '9.0.19'
    },{
      'min_version': '10',
      'fixed_version': '10.0.11'
    }]
  }]
};

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