Linux Distros Unpatched Vulnerability : CVE-2026-126073

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

include('compat.inc');

if (description)
{
  script_id(379188);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/13");

  script_cve_id("CVE-2026-126073");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-126073");

  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.

  - Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2,
    Action Pack negotiates the format of a rendered response from the Accept, X-Requested-With and, for XHR
    requests without Accept, Content-Type request headers, but ActionController::Rendering#_set_vary_header
    adds Vary: Accept only when the request carries a usable Accept header and the response has no Vary header
    yet. A response to a request without Accept, or to an XHR request, therefore omits the headers that
    selected its representation, and a response whose Vary the application set before rendering (for example
    Vary: Accept-Language) never gains Accept. A shared cache that honours Vary could store such a response
    and serve it to later clients that request a different representation, possibly leading to cache poisoning
    in which visitors receive, until the entry expires, a page without its layout or HTML in place of JSON.
    The attacker cannot choose the content of the response. Applications that render negotiated responses from
    actions marked public (for example with expires_in ..., public: true) behind a shared cache that honours
    Vary, such as Thruster or Rack::Cache, are affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
    (CVE-2026-126073)

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-2026-126073");
  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:H/Au:N/C:N/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:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-126073");

  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:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  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:rails");
  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-12", "Host/OS/Debian Linux-13", "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-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "rails"},
          {"reference": "ruby-actioncable"},
          {"reference": "ruby-actionmailbox"},
          {"reference": "ruby-actionmailer"},
          {"reference": "ruby-actionpack"},
          {"reference": "ruby-actiontext"},
          {"reference": "ruby-actionview"},
          {"reference": "ruby-activejob"},
          {"reference": "ruby-activemodel"},
          {"reference": "ruby-activerecord"},
          {"reference": "ruby-activestorage"},
          {"reference": "ruby-activesupport"},
          {"reference": "ruby-rails"},
          {"reference": "ruby-railties"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "rails"},
          {"reference": "ruby-actioncable"},
          {"reference": "ruby-actionmailbox"},
          {"reference": "ruby-actionmailer"},
          {"reference": "ruby-actionpack"},
          {"reference": "ruby-actiontext"},
          {"reference": "ruby-actionview"},
          {"reference": "ruby-activejob"},
          {"reference": "ruby-activemodel"},
          {"reference": "ruby-activerecord"},
          {"reference": "ruby-activestorage"},
          {"reference": "ruby-activesupport"},
          {"reference": "ruby-rails"},
          {"reference": "ruby-railties"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "rails"},
          {"reference": "ruby-actioncable"},
          {"reference": "ruby-actionmailbox"},
          {"reference": "ruby-actionmailer"},
          {"reference": "ruby-actionpack"},
          {"reference": "ruby-actiontext"},
          {"reference": "ruby-actionview"},
          {"reference": "ruby-activejob"},
          {"reference": "ruby-activemodel"},
          {"reference": "ruby-activerecord"},
          {"reference": "ruby-activestorage"},
          {"reference": "ruby-activesupport"},
          {"reference": "ruby-rails"},
          {"reference": "ruby-railties"}
        ]
      }
    ]
  }
};

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');
}