Linux Distros Unpatched Vulnerability : CVE-2026-126135

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

include('compat.inc');

if (description)
{
  script_id(378756);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/12");

  script_cve_id("CVE-2026-126135");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-126135");

  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.

  - If an attacker was able to perform a man-in-the-middle attack on an SMTP or POP3 server connection using
    STARTTLS, the attacker could inject server responses before the TLS handshake completed. Thunderbird would
    process these responses after the handshake, as if they had been received from the server over the
    encrypted connection. This could be used to make Thunderbird report a different outcome for sending or
    fetching mail, and to show attacker-controlled text in error messages. The encrypted connection itself was
    not compromised, and credentials were not exposed. Connections using SSL/TLS instead of STARTTLS were not
    affected. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7. (CVE-2026-126135)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-126135");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-126135");
  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:M/Au:N/C:P/I:N/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:H/PR:N/UI:N/S:U/C:H/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-2026-126135");

  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:"2026/11/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/11/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:thunderbird");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:thunderbird");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_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/CentOS Linux-8", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-14", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9");

  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/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "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"}
        ]
      }
    ]
  },
  "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"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "thunderbird"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "thunderbird"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "thunderbird"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "thunderbird"}
        ]
      }
    ]
  }
};

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');
}