Linux Distros Unpatched Vulnerability : CVE-2026-99251

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

include('compat.inc');

if (description)
{
  script_id(375569);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/03");

  script_cve_id("CVE-2026-99251");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-99251");

  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.

  - Drivers: hv: Avoid infinite retry loop in init_vp_index() There is a retry loop in init_vp_index() where
    the CPUs from a certain node are stripped out if they have already been in the allocated cpumask or not in
    HK_TYPE_MANAGED_IRQ housekeeping cpumask. If there is no CPU left, the allocated cpumask is ignored and
    the process is retried again. However, if the HK_TYPE_MANAGED_IRQ housekeeping cpumask turns out not to
    contain any CPU in that particular node, that will become an infinite retry loop. This particular problem
    was reported by sashiko [1]. This should rarely happen, but we still need to guard against this. Fix this
    infinite loop problem by also skipping NUMA node that has no housekeeping CPU in the inner while loop of
    init_vp_index(). Also update the early abort check to check for the absence of online housekeeping CPUs
    instead of just the emptiness of the cpumask. As the outer for loop will only be reached if the
    housekeeping cpumask has at least one online CPU, a NUMA node with housekeeping CPUs will eventually be
    found. (CVE-2026-99251)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-99251");
  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:N/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:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-99251");

  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:"2026/11/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/11/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:linux");
  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/Debian Linux-12", "Host/OS/Debian Linux-14");

  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/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "btrfs-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "cdrom-core-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "ext4-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "fat-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "isofs-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "jfs-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "kernel-image-6.1.0-50-alpha-generic-di"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-6.1"},
          {"reference": "linux-headers-6.1.0"},
          {"reference": "linux-source"},
          {"reference": "linux-source-6.1"},
          {"reference": "linux-support-6.1.0"},
          {"reference": "loop-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "nic-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "nic-shared-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "nic-wireless-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "pata-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "ppp-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "scsi-core-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "scsi-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "scsi-nic-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "serial-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "usb-serial-modules-6.1.0-50-alpha-generic-di"},
          {"reference": "xfs-modules-6.1.0-50-alpha-generic-di"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "bpftool"},
          {"reference": "hyperv-daemons"},
          {"reference": "intel-sdsi"},
          {"reference": "libcpupower-dev"},
          {"reference": "libcpupower1"},
          {"reference": "linux-base-7.2.12+deb14-alpha-generic"},
          {"reference": "linux-base-7.2.12+deb14-amd64"},
          {"reference": "linux-base-7.2.12+deb14-arm64"},
          {"reference": "linux-base-7.2.12+deb14-arm64-16k"},
          {"reference": "linux-base-7.2.12+deb14-armmp"},
          {"reference": "linux-base-7.2.12+deb14-armmp-lpae"},
          {"reference": "linux-base-7.2.12+deb14-cloud-amd64"},
          {"reference": "linux-base-7.2.12+deb14-cloud-arm64"},
          {"reference": "linux-base-7.2.12+deb14-loong64"},
          {"reference": "linux-base-7.2.12+deb14-m68k"},
          {"reference": "linux-base-7.2.12+deb14-parisc"},
          {"reference": "linux-base-7.2.12+deb14-parisc64"},
          {"reference": "linux-base-7.2.12+deb14-powerpc"},
          {"reference": "linux-base-7.2.12+deb14-powerpc64"},
          {"reference": "linux-base-7.2.12+deb14-powerpc64-64k"},
          {"reference": "linux-base-7.2.12+deb14-powerpc64le"},
          {"reference": "linux-base-7.2.12+deb14-powerpc64le-64k"},
          {"reference": "linux-base-7.2.12+deb14-riscv64"},
          {"reference": "linux-base-7.2.12+deb14-rt-amd64"},
          {"reference": "linux-base-7.2.12+deb14-rt-arm64"},
          {"reference": "linux-base-7.2.12+deb14-s390x"},
          {"reference": "linux-base-7.2.12+deb14-sh7751r"},
          {"reference": "linux-base-7.2.12+deb14-sparc64"},
          {"reference": "linux-base-7.2.12+deb14-test"},
          {"reference": "linux-base-alpha-generic"},
          {"reference": "linux-base-armmp"},
          {"reference": "linux-base-armmp-lpae"},
          {"reference": "linux-base-loong64"}
        ]
      }
    ]
  }
};

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');
}