Linux Distros Unpatched Vulnerability : CVE-2026-18654

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

include('compat.inc');

if (description)
{
  script_id(342175);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/02");

  script_cve_id("CVE-2026-18654");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-18654");

  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.

  - Key exchange without entity authentication in the EMR SSH helper commands in Amazon AWS CLI before 1.45.28
    and AWS CLI v2 before 2.35.3 might allow man-in-the-middle attackers to intercept SSHsessions and file
    transfers via network positioning between the client and the EMR cluster endpoint. To remediate this
    issue, users should upgrade to AWS CLI v1 1.45.28 or later, or AWS CLI v2 2.35.3 or later.
    (CVE-2026-18654)

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-2026-18654");
  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:C/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:C/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-18654");

  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:"2026/08/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/01");

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  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-7", "Host/OS/CentOS Linux-8", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-7", "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/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": "awscli2"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "awscli"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "awscli"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "awscli"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "awscli"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "awscli2"},
          {"reference": "fence-agents"},
          {"reference": "fence-agents-aliyun"},
          {"reference": "fence-agents-all"},
          {"reference": "fence-agents-amt-ws"},
          {"reference": "fence-agents-apc"},
          {"reference": "fence-agents-apc-snmp"},
          {"reference": "fence-agents-aws"},
          {"reference": "fence-agents-azure-arm"},
          {"reference": "fence-agents-bladecenter"},
          {"reference": "fence-agents-brocade"},
          {"reference": "fence-agents-cisco-mds"},
          {"reference": "fence-agents-cisco-ucs"},
          {"reference": "fence-agents-common"},
          {"reference": "fence-agents-compute"},
          {"reference": "fence-agents-drac5"},
          {"reference": "fence-agents-eaton-snmp"},
          {"reference": "fence-agents-emerson"},
          {"reference": "fence-agents-eps"},
          {"reference": "fence-agents-gce"},
          {"reference": "fence-agents-heuristics-ping"},
          {"reference": "fence-agents-hpblade"},
          {"reference": "fence-agents-ibm-powervs"},
          {"reference": "fence-agents-ibm-vpc"},
          {"reference": "fence-agents-ibmblade"},
          {"reference": "fence-agents-ifmib"},
          {"reference": "fence-agents-ilo-moonshot"},
          {"reference": "fence-agents-ilo-mp"},
          {"reference": "fence-agents-ilo-ssh"},
          {"reference": "fence-agents-ilo2"},
          {"reference": "fence-agents-intelmodular"},
          {"reference": "fence-agents-ipdu"},
          {"reference": "fence-agents-ipmilan"},
          {"reference": "fence-agents-kdump"},
          {"reference": "fence-agents-kubevirt"},
          {"reference": "fence-agents-lpar"},
          {"reference": "fence-agents-mpath"},
          {"reference": "fence-agents-nutanix-ahv"},
          {"reference": "fence-agents-openstack"},
          {"reference": "fence-agents-redfish"},
          {"reference": "fence-agents-rhevm"},
          {"reference": "fence-agents-rsa"},
          {"reference": "fence-agents-rsb"},
          {"reference": "fence-agents-sbd"},
          {"reference": "fence-agents-scsi"},
          {"reference": "fence-agents-virsh"},
          {"reference": "fence-agents-vmware-rest"},
          {"reference": "fence-agents-vmware-soap"},
          {"reference": "fence-agents-wti"},
          {"reference": "fence-agents-zvm"},
          {"reference": "fence-virt"},
          {"reference": "fence-virtd"},
          {"reference": "fence-virtd-cpg"},
          {"reference": "fence-virtd-libvirt"},
          {"reference": "fence-virtd-multicast"},
          {"reference": "fence-virtd-serial"},
          {"reference": "fence-virtd-tcp"},
          {"reference": "ha-cloud-support"}
        ]
      }
    ]
  }
};

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');
}