Linux Distros Unpatched Vulnerability : CVE-2026-118131

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

include('compat.inc');

if (description)
{
  script_id(373380);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/28");

  script_cve_id("CVE-2026-118131");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-118131");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - GnuPG (version 2.5.21) for Windows contains a vulnerability where default Discretionary Access Control
    List (DACL) inheritance on the C:\ProgramData directory allows members of the BUILTIN\Users group to
    create arbitrary subdirectories under this path. An attacker with low-privilege access can create the
    expected GnuPG configuration directory and inject malicious configuration files consumed by GnuPG
    components. This can result in code execution within the security context of the victim user.
    (CVE-2026-118131)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-118131");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-118131");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnupg2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

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

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "Host/OS/Ubuntu Linux-26.04", "Host/OS/Ubuntu Linux-26.10");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg2"},
          {"reference": "gpgsm"},
          {"reference": "gpgv-udeb"},
          {"reference": "gpgv2"},
          {"reference": "scdaemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "gpgv-win32"},
          {"reference": "gpgv2"},
          {"reference": "scdaemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "gpgv-win32"},
          {"reference": "gpgv2"},
          {"reference": "scdaemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "gpgv-win32"},
          {"reference": "gpgv2"},
          {"reference": "scdaemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "gpgv-win32"},
          {"reference": "keyboxd"},
          {"reference": "scdaemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "scdaemon"},
          {"reference": "tpm2daemon"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.10",
        "pkgs": [
          {"reference": "dirmngr"},
          {"reference": "gnupg"},
          {"reference": "gnupg-agent"},
          {"reference": "gnupg-l10n"},
          {"reference": "gnupg-utils"},
          {"reference": "gnupg2"},
          {"reference": "gpg"},
          {"reference": "gpg-agent"},
          {"reference": "gpg-wks-client"},
          {"reference": "gpg-wks-server"},
          {"reference": "gpgconf"},
          {"reference": "gpgsm"},
          {"reference": "gpgv"},
          {"reference": "gpgv-static"},
          {"reference": "gpgv-udeb"},
          {"reference": "scdaemon"},
          {"reference": "tpm2daemon"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}