Linux Distros Unpatched Vulnerability : CVE-2026-84394

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

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  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/03");

  script_cve_id("CVE-2026-84394");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-84394");

  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.

  - fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an
    error. A host that starts with an opening bracket but does not end with a closing bracket is neither
    validated as an IP literal nor canonicalized as a domain name, so parse() returns it as the host with
    error undefined, while Node's URL and the HTTP clients built on it resolve the same string to a different
    host. An application that reads the parsed host to make a host decision, such as an SSRF denylist, a
    redirect allowlist, or proxy routing, and then passes the original URL to an HTTP client evaluates its
    policy against a string that is not the host the request reaches. The same host is carried through
    normalize, equal, and resolve. This affects fast-uri versions 2.4.5, 3.1.6, and 4.1.3, and is fixed in
    2.4.6, 3.1.7, and 4.1.4, where parse() reports a malformed host for any host that contains a bracket but
    is not a valid IPv6 literal. (CVE-2026-84394)

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-2026-84394");
  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:P/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:N/S:U/C:N/I:H/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-2026-84394");

  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:"2026/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/03");

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  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/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9");

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}

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/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "aspnetcore-runtime-8.0"},
          {"reference": "aspnetcore-runtime-dbg-8.0"},
          {"reference": "aspnetcore-targeting-pack-8.0"},
          {"reference": "cockpit-image-builder"},
          {"reference": "dotnet-apphost-pack-8.0"},
          {"reference": "dotnet-hostfxr-8.0"},
          {"reference": "dotnet-runtime-8.0"},
          {"reference": "dotnet-runtime-dbg-8.0"},
          {"reference": "dotnet-sdk-8.0"},
          {"reference": "dotnet-sdk-8.0-source-built-artifacts"},
          {"reference": "dotnet-sdk-dbg-8.0"},
          {"reference": "dotnet-targeting-pack-8.0"},
          {"reference": "dotnet-templates-8.0"},
          {"reference": "dotnet8.0"},
          {"reference": "grafana"},
          {"reference": "grafana-pcp"},
          {"reference": "grafana-selinux"},
          {"reference": "linux-sgx"},
          {"reference": "sgx-common"},
          {"reference": "sgx-libs"},
          {"reference": "sgx-mpa"},
          {"reference": "sgx-pccs"},
          {"reference": "sgx-pccs-admin"},
          {"reference": "sgx-pckid-tool"},
          {"reference": "tdx-qgs"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "aspnetcore-runtime-8.0"},
          {"reference": "aspnetcore-runtime-dbg-8.0"},
          {"reference": "aspnetcore-targeting-pack-8.0"},
          {"reference": "dotnet"},
          {"reference": "dotnet-apphost-pack-8.0"},
          {"reference": "dotnet-host"},
          {"reference": "dotnet-hostfxr-8.0"},
          {"reference": "dotnet-runtime-8.0"},
          {"reference": "dotnet-runtime-dbg-8.0"},
          {"reference": "dotnet-sdk-8.0"},
          {"reference": "dotnet-sdk-8.0-source-built-artifacts"},
          {"reference": "dotnet-sdk-dbg-8.0"},
          {"reference": "dotnet-targeting-pack-8.0"},
          {"reference": "dotnet-templates-8.0"},
          {"reference": "dotnet8.0"},
          {"reference": "netstandard-targeting-pack-2.1"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "aspnetcore-runtime-8.0"},
          {"reference": "aspnetcore-runtime-dbg-8.0"},
          {"reference": "aspnetcore-targeting-pack-8.0"},
          {"reference": "dotnet"},
          {"reference": "dotnet-apphost-pack-8.0"},
          {"reference": "dotnet-host"},
          {"reference": "dotnet-hostfxr-8.0"},
          {"reference": "dotnet-runtime-8.0"},
          {"reference": "dotnet-runtime-dbg-8.0"},
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          {"reference": "dotnet8.0"},
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      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "aspnetcore-runtime-8.0"},
          {"reference": "aspnetcore-runtime-dbg-8.0"},
          {"reference": "aspnetcore-targeting-pack-8.0"},
          {"reference": "dotnet-apphost-pack-8.0"},
          {"reference": "dotnet-host"},
          {"reference": "dotnet-hostfxr-8.0"},
          {"reference": "dotnet-runtime-8.0"},
          {"reference": "dotnet-runtime-dbg-8.0"},
          {"reference": "dotnet-sdk-8.0"},
          {"reference": "dotnet-sdk-8.0-source-built-artifacts"},
          {"reference": "dotnet-sdk-dbg-8.0"},
          {"reference": "dotnet-targeting-pack-8.0"},
          {"reference": "dotnet-templates-8.0"},
          {"reference": "dotnet8.0"},
          {"reference": "linux-sgx"},
          {"reference": "netstandard-targeting-pack-2.1"},
          {"reference": "sgx-common"},
          {"reference": "sgx-libs"},
          {"reference": "sgx-mpa"},
          {"reference": "sgx-pccs"},
          {"reference": "sgx-pccs-admin"},
          {"reference": "sgx-pckid-tool"},
          {"reference": "tdx-qgs"}
        ]
      }
    ]
  }
};

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');
}