Linux Distros Unpatched Vulnerability : CVE-2026-99252

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

include('compat.inc');

if (description)
{
  script_id(375579);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/03");

  script_cve_id("CVE-2026-99252");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-99252");

  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.

  - io_uring/mpscq: disable preemption while pushing A push makes the node the new tail, and then links it to
    its predecessor. In between the queue isn't empty, but mpscq_pop() can't get at the node. The consumers
    deal with that by trying again, with a cond_resched() in the loop to give a preempted producer the chance
    to finish. cond_resched() doesn't do that if the consumer has a higher priority than the producer and both
    have to use the same CPU: producer (SCHED_OTHER) consumer (SCHED_FIFO), same CPU io_req_local_work_add()
    mpscq_push() prev = xchg(&q->tail, node) <preempted> io_cqring_wait() __io_run_local_work() again:
    cond_resched() // nothing to do mpscq_pop() // NULL // work pending, no events yet goto again The producer
    can be any task that is able to queue task_work for the ring: an io-wq worker, or somebody who sends a
    message with IORING_OP_MSG_RING. The consumer spins, holding ->uring_lock, until the scheduler takes pity
    on the fair class, which takes about a second with the default settings of the fair server, and forever
    without it. The loops in tctx_task_work_run() and io_cancel_local_task_work() have the same problem. Don't
    allow preemption between the two steps. That bounds the time the window is open on the CPU of the producer
    by what interrupts take, and a consumer that waits for that is on another CPU. The cost is a
    preempt_disable()/preempt_enable() pair per push. (CVE-2026-99252)

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-2026-99252");
  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-2026-99252");

  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: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-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-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');
}