RHEL 8 : kernel-rt (RHSA-2026:85774)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2026:85774. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(367757);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/20");

  script_cve_id(
    "CVE-2026-52935",
    "CVE-2026-53196",
    "CVE-2026-74588",
    "CVE-2026-74752",
    "CVE-2026-89479",
    "CVE-2026-89631",
    "CVE-2026-93288",
    "CVE-2026-93817",
    "CVE-2026-98320"
  );
  script_xref(name:"RHSA", value:"2026:85774");

  script_name(english:"RHEL 8 : kernel-rt (RHSA-2026:85774)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates.");
  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-2026:85774 advisory.

    The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with
    extremely high determinism requirements.

    Security Fix(es):

    * kernel: xfrm: espintcp: do not reuse an in-progress partial send (CVE-2026-52935)

    * kernel: USB: serial: io_ti: fix heap overflow in get_manuf_info() (CVE-2026-53196)

    * kernel: sctp: keep chunk->transport in step with the list it is queued on (CVE-2026-74588)

    * kernel: sctp: validate cookie AUTH state before use (CVE-2026-74752)

    * kernel: smb: client: reject a tree connect response whose byte count is too small (CVE-2026-89631)

    * kernel: sctp: stop processing a packet once its association is deleted (CVE-2026-89479)

    * kernel: perf: Fix addr_filter_ranges lifetime (CVE-2026-93817)

    * kernel: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state (CVE-2026-93288)

    * kernel: kernel: strparser: use-after-free via msg_timer_work rearm after strp_done() cancellation ()

    * kernel: netfilter: flowtable: hold reference on ct until flow is released (CVE-2026-98320)

    Bug Fix(es) and Enhancement(s):

    *  gfs2 filesystem withdrawal rework [RHEL-8] (JIRA:RHEL-129363)

    * Batch: z-stream xfrm - rhel-8.10.z (NST-Core-26W38) (JIRA:RHEL-256684)

    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=2492098");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2492750");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2521384");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2524422");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2532089");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2532290");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2540391");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2540500");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2540872");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2546494");
  # https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_85774.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a5ae2f78");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:85774");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-53196");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(125, 787, 805, 825);
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/20");

  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:kernel-rt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra");
  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_info2.nasl", "redhat_repos.nasl", "linux_alt_patch_detect.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');
include('ksplice.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);

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var livepatch_source = get_one_kb_item('Host/livepatch-kernel-source');
  if (empty_or_null(livepatch_source)) livepatch_source = 'KSplice';
  rm_kb_item(name:'Host/livepatch-kernel-version');

  var cve_list = make_list('CVE-2026-52935', 'CVE-2026-53196', 'CVE-2026-74588', 'CVE-2026-74752', 'CVE-2026-89479', 'CVE-2026-89631', 'CVE-2026-93288', 'CVE-2026-93817', 'CVE-2026-98320');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, livepatch_source + ' hotfix for RHSA-2026:85774');
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

var constraints = [
  {
    'release': '8',
    'repo_relative_urls': [
      'content/dist/rhel8/8.10/x86_64/nfv/debug',
      'content/dist/rhel8/8.10/x86_64/nfv/os',
      'content/dist/rhel8/8.10/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.10/x86_64/rt/debug',
      'content/dist/rhel8/8.10/x86_64/rt/os',
      'content/dist/rhel8/8.10/x86_64/rt/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/nfv/debug',
      'content/dist/rhel8/8.6/x86_64/nfv/os',
      'content/dist/rhel8/8.6/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/rt/debug',
      'content/dist/rhel8/8.6/x86_64/rt/os',
      'content/dist/rhel8/8.6/x86_64/rt/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/nfv/debug',
      'content/dist/rhel8/8.8/x86_64/nfv/os',
      'content/dist/rhel8/8.8/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/rt/debug',
      'content/dist/rhel8/8.8/x86_64/rt/os',
      'content/dist/rhel8/8.8/x86_64/rt/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/nfv/debug',
      'content/dist/rhel8/8.9/x86_64/nfv/os',
      'content/dist/rhel8/8.9/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/rt/debug',
      'content/dist/rhel8/8.9/x86_64/rt/os',
      'content/dist/rhel8/8.9/x86_64/rt/source/SRPMS',
      'content/dist/rhel8/8/x86_64/nfv/debug',
      'content/dist/rhel8/8/x86_64/nfv/os',
      'content/dist/rhel8/8/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8/x86_64/rt/debug',
      'content/dist/rhel8/8/x86_64/rt/os',
      'content/dist/rhel8/8/x86_64/rt/source/SRPMS',
      'content/e6s/rhel8/8.10/x86_64/nfv/debug',
      'content/e6s/rhel8/8.10/x86_64/nfv/os',
      'content/e6s/rhel8/8.10/x86_64/nfv/source/SRPMS',
      'content/e6s/rhel8/8.10/x86_64/rt/debug',
      'content/e6s/rhel8/8.10/x86_64/rt/os',
      'content/e6s/rhel8/8.10/x86_64/rt/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'kernel-rt-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-core-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-debug-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-debug-core-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-debug-devel-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-debug-modules-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-debug-modules-extra-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-devel-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-modules-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-modules-extra-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '8',
    'repo_relative_urls': [
      'content/dist/rhel8/8.10/x86_64/nfv/debug',
      'content/dist/rhel8/8.10/x86_64/nfv/os',
      'content/dist/rhel8/8.10/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.6/x86_64/nfv/debug',
      'content/dist/rhel8/8.6/x86_64/nfv/os',
      'content/dist/rhel8/8.6/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.8/x86_64/nfv/debug',
      'content/dist/rhel8/8.8/x86_64/nfv/os',
      'content/dist/rhel8/8.8/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8.9/x86_64/nfv/debug',
      'content/dist/rhel8/8.9/x86_64/nfv/os',
      'content/dist/rhel8/8.9/x86_64/nfv/source/SRPMS',
      'content/dist/rhel8/8/x86_64/nfv/debug',
      'content/dist/rhel8/8/x86_64/nfv/os',
      'content/dist/rhel8/8/x86_64/nfv/source/SRPMS',
      'content/e6s/rhel8/8.10/x86_64/nfv/debug',
      'content/e6s/rhel8/8.10/x86_64/nfv/os',
      'content/e6s/rhel8/8.10/x86_64/nfv/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'kernel-rt-debug-kvm-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-rt-kvm-4.18.0-553.176.1.rt7.517.el8_10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

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, 'kernel-rt / kernel-rt-core / kernel-rt-debug / kernel-rt-debug-core / etc');
}