Linux Distros Unpatched Vulnerability : CVE-2026-84837

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

include('compat.inc');

if (description)
{
  script_id(342382);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/03");

  script_cve_id("CVE-2026-84837");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-84837");

  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.

  - A flaw was found in rpm. An attacker can exploit a command injection vulnerability by influencing the path
    or filename of a tarball processed by `rpmbuild -t*` to include shell metacharacters. This is particularly
    relevant in automated build or continuous integration (CI) workflows that ingest externally supplied
    artifact names. Successful exploitation allows for arbitrary command execution with the privileges of the
    build user, which could lead to information disclosure or disruption of the build environment.
    (CVE-2026-84837)

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-2026-84837");
  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:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-84837");

  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:"2026/09/02");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  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:python3-rpm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-apidocs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-build");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-build-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-cron");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-audit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-dbus-announce");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-fapolicyd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-ima");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-prioreset");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-selinux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-syslog");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-plugin-systemd-inhibit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-python");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-sign");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:rpm-sign-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python3-rpm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-apidocs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-build");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-build-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-cron");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-audit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-dbus-announce");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-fapolicyd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-ima");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-prioreset");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-selinux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-syslog");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-plugin-systemd-inhibit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-python");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-sign");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpm-sign-libs");
  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-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": "python3-rpm"},
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-audit"},
          {"reference": "rpm-plugin-dbus-announce"},
          {"reference": "rpm-plugin-fapolicyd"},
          {"reference": "rpm-plugin-ima"},
          {"reference": "rpm-plugin-selinux"},
          {"reference": "rpm-plugin-syslog"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-sign"},
          {"reference": "rpm-sign-libs"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-python"},
          {"reference": "rpm-sign"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-python"},
          {"reference": "rpm-sign"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "python3-rpm"},
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-fapolicyd"},
          {"reference": "rpm-plugin-ima"},
          {"reference": "rpm-plugin-prioreset"},
          {"reference": "rpm-plugin-selinux"},
          {"reference": "rpm-plugin-syslog"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-sign"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "python3-rpm"},
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-fapolicyd"},
          {"reference": "rpm-plugin-ima"},
          {"reference": "rpm-plugin-prioreset"},
          {"reference": "rpm-plugin-selinux"},
          {"reference": "rpm-plugin-syslog"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-sign"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "python3-rpm"},
          {"reference": "rpm"},
          {"reference": "rpm-apidocs"},
          {"reference": "rpm-build"},
          {"reference": "rpm-build-libs"},
          {"reference": "rpm-cron"},
          {"reference": "rpm-devel"},
          {"reference": "rpm-libs"},
          {"reference": "rpm-plugin-audit"},
          {"reference": "rpm-plugin-fapolicyd"},
          {"reference": "rpm-plugin-ima"},
          {"reference": "rpm-plugin-selinux"},
          {"reference": "rpm-plugin-syslog"},
          {"reference": "rpm-plugin-systemd-inhibit"},
          {"reference": "rpm-sign"},
          {"reference": "rpm-sign-libs"}
        ]
      }
    ]
  }
};

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_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}