RHEL 8 : bind9.16 (RHSA-2026:54509)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2026:54509. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(335125);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/13");

  script_cve_id(
    "CVE-2026-10723",
    "CVE-2026-11331",
    "CVE-2026-11622",
    "CVE-2026-11721",
    "CVE-2026-13204",
    "CVE-2026-13321"
  );
  script_xref(name:"RHSA", value:"2026:54509");

  script_name(english:"RHEL 8 : bind9.16 (RHSA-2026:54509)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates for bind9.16.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as
referenced in the RHSA-2026:54509 advisory.

    The Berkeley Internet Name Domain (BIND) is an implementation of the Domain Name System (DNS) protocols.
    BIND includes a DNS server (named); a resolver library (routines for applications to use when interfacing
    with DNS); and tools for verifying that the DNS server is operating correctly.

    Security Fix(es):

    * bind9: bind: Potential wildcard CNAME RPZ policy bypass (CVE-2026-11331)

    * bind: bind9: DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field (CVE-2026-13321)

    * bind: bind9: Potential memory usage beyond configured limits (CVE-2026-11622)

    * bind: bind9: Cache poisoning via label count discrepancy, RRSIG, wildcards (CVE-2026-11721)

    * bind: bind9: Unexpected exit with NSEC and NSEC3 both present (CVE-2026-13204)

    * bind: bind9: Incorrect acceptance of NSEC3 records (CVE-2026-10723)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and
    other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/updates/classification/#important");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2503721");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2504166");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2504298");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2504338");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2504447");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2504560");
  # https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_54509.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ac81f072");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:54509");
  script_set_attribute(attribute:"solution", value:
"Update the RHEL bind9.16 package based on the guidance in RHSA-2026:54509.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-13321");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(345, 400, 617);
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/07/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_eus:8.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-chroot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-dnssec-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-license");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:bind9.16-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python3-bind9.16");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Red Hat Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "redhat_repos.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm2.inc');
include('rhel.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'Red Hat' >!< os_product) audit(AUDIT_OS_NOT, 'Red Hat');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
if (!rhel_check_release(operator: 'ge', os_version: os_version, rhel_version: '8')) audit(AUDIT_OS_NOT, 'Red Hat 8.x', 'Red Hat ' + os_version);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'release': '8',
    'repo_relative_urls': [
      'content/dist/rhel8/8.10/x86_64/appstream/debug',
      'content/dist/rhel8/8.10/x86_64/appstream/os',
      'content/dist/rhel8/8.10/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.10/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.10/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.10/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/appstream/debug',
      'content/dist/rhel8/8.6/x86_64/appstream/os',
      'content/dist/rhel8/8.6/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/appstream/debug',
      'content/dist/rhel8/8.8/x86_64/appstream/os',
      'content/dist/rhel8/8.8/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/appstream/debug',
      'content/dist/rhel8/8.9/x86_64/appstream/os',
      'content/dist/rhel8/8.9/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8/x86_64/appstream/debug',
      'content/dist/rhel8/8/x86_64/appstream/os',
      'content/dist/rhel8/8/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8/x86_64/codeready-builder/os',
      'content/dist/rhel8/8/x86_64/codeready-builder/source/SRPMS',
      'content/e6s/rhel8/8.10/x86_64/appstream/debug',
      'content/e6s/rhel8/8.10/x86_64/appstream/os',
      'content/e6s/rhel8/8.10/x86_64/appstream/source/SRPMS',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/debug',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/os',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/source/SRPMS',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/debug',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/os',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'bind9.16-libs-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-libs-9.16.23-0.22.el8_10.12', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'}
    ]
  },
  {
    'release': '8',
    'repo_relative_urls': [
      'content/dist/rhel8/8.10/x86_64/appstream/debug',
      'content/dist/rhel8/8.10/x86_64/appstream/os',
      'content/dist/rhel8/8.10/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/appstream/debug',
      'content/dist/rhel8/8.6/x86_64/appstream/os',
      'content/dist/rhel8/8.6/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/appstream/debug',
      'content/dist/rhel8/8.8/x86_64/appstream/os',
      'content/dist/rhel8/8.8/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/appstream/debug',
      'content/dist/rhel8/8.9/x86_64/appstream/os',
      'content/dist/rhel8/8.9/x86_64/appstream/source/SRPMS',
      'content/dist/rhel8/8/x86_64/appstream/debug',
      'content/dist/rhel8/8/x86_64/appstream/os',
      'content/dist/rhel8/8/x86_64/appstream/source/SRPMS',
      'content/e6s/rhel8/8.10/x86_64/appstream/debug',
      'content/e6s/rhel8/8.10/x86_64/appstream/os',
      'content/e6s/rhel8/8.10/x86_64/appstream/source/SRPMS',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/debug',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/os',
      'content/public/ubi/dist/ubi8/8/x86_64/appstream/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'bind9.16-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-chroot-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-dnssec-utils-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-license-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-utils-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'python3-bind9.16-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'}
    ]
  },
  {
    'release': '8',
    'repo_relative_urls': [
      'content/dist/rhel8/8.10/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.10/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.10/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.6/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.8/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/os',
      'content/dist/rhel8/8.9/x86_64/codeready-builder/source/SRPMS',
      'content/dist/rhel8/8/x86_64/codeready-builder/debug',
      'content/dist/rhel8/8/x86_64/codeready-builder/os',
      'content/dist/rhel8/8/x86_64/codeready-builder/source/SRPMS',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/debug',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/os',
      'content/public/ubi/dist/ubi8/8/x86_64/codeready-builder/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'bind9.16-devel-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'},
      {'reference':'bind9.16-doc-9.16.23-0.22.el8_10.12', 'rpm_spec_vers_cmp':TRUE, 'epoch':'32'}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var repo_relative_urls;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }

  if (!empty_or_null(constraint['repo_relative_urls'])) repo_relative_urls = constraint['repo_relative_urls'];

  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!exists_check || rpm_exists(rpm:exists_check))) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = rpm_report_get() + redhat_report_repo_caveat();
  else extra = rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'bind9.16 / bind9.16-chroot / bind9.16-devel / bind9.16-dnssec-utils / etc');
}