Linux Distros Unpatched Vulnerability : CVE-2026-0818

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

include('compat.inc');

if (description)
{
  script_id(297038);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/04");

  script_cve_id("CVE-2026-0818");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-0818");

  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.

  - When a user explicitly requested Thunderbird to decrypt an inline OpenPGP message that was embedded in a
    text section of an email that was formatted and styled with HTML and CSS, then the decrypted contents were
    rendered in a context in which the CSS styles from the outer messages were active. If the user had
    additionally allowed loading of the remote content referenced by the outer email message, and the email
    was crafted by the sender using a combination of CSS rules and fonts and animations, then it was possible
    to extract the secret contents of the email. This vulnerability affects Thunderbird < 147.0.1 and
    Thunderbird < 140.7.1. (CVE-2026-0818)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-0818");
  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:N/AC:L/Au:N/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-0818");

  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:"plugin_publication_date", value:"2026/01/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:thunderbird");
  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/Debian Linux-14");

  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 = {
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "thunderbird"},
          {"reference": "thunderbird-l10n-af"},
          {"reference": "thunderbird-l10n-all"},
          {"reference": "thunderbird-l10n-ar"},
          {"reference": "thunderbird-l10n-ast"},
          {"reference": "thunderbird-l10n-be"},
          {"reference": "thunderbird-l10n-bg"},
          {"reference": "thunderbird-l10n-br"},
          {"reference": "thunderbird-l10n-ca"},
          {"reference": "thunderbird-l10n-cak"},
          {"reference": "thunderbird-l10n-cs"},
          {"reference": "thunderbird-l10n-cy"},
          {"reference": "thunderbird-l10n-da"},
          {"reference": "thunderbird-l10n-de"},
          {"reference": "thunderbird-l10n-dsb"},
          {"reference": "thunderbird-l10n-el"},
          {"reference": "thunderbird-l10n-en-ca"},
          {"reference": "thunderbird-l10n-en-gb"},
          {"reference": "thunderbird-l10n-es-ar"},
          {"reference": "thunderbird-l10n-es-es"},
          {"reference": "thunderbird-l10n-es-mx"},
          {"reference": "thunderbird-l10n-et"},
          {"reference": "thunderbird-l10n-eu"},
          {"reference": "thunderbird-l10n-fi"},
          {"reference": "thunderbird-l10n-fr"},
          {"reference": "thunderbird-l10n-fy-nl"},
          {"reference": "thunderbird-l10n-ga-ie"},
          {"reference": "thunderbird-l10n-gd"},
          {"reference": "thunderbird-l10n-gl"},
          {"reference": "thunderbird-l10n-he"},
          {"reference": "thunderbird-l10n-hr"},
          {"reference": "thunderbird-l10n-hsb"},
          {"reference": "thunderbird-l10n-hu"},
          {"reference": "thunderbird-l10n-hy-am"},
          {"reference": "thunderbird-l10n-id"},
          {"reference": "thunderbird-l10n-is"},
          {"reference": "thunderbird-l10n-it"},
          {"reference": "thunderbird-l10n-ja"},
          {"reference": "thunderbird-l10n-ka"},
          {"reference": "thunderbird-l10n-kab"},
          {"reference": "thunderbird-l10n-kk"},
          {"reference": "thunderbird-l10n-ko"},
          {"reference": "thunderbird-l10n-lt"},
          {"reference": "thunderbird-l10n-lv"},
          {"reference": "thunderbird-l10n-ms"}
        ]
      }
    ]
  }
};

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 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');
}