Linux Distros Unpatched Vulnerability : CVE-2026-89677

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

include('compat.inc');

if (description)
{
  script_id(345148);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/12");

  script_cve_id("CVE-2026-89677");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-89677");

  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.

  - nfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file() dentry_create() can hypothetically
    provide a different dentry than the one passed in. This could happen, for example, if the exported
    filesystem is NFS, and the server returned to OPEN a filehandle which matched a directory that was already
    in the dcache. Clearly this would not be expected! If this were to happen the dentry (child) that was
    already stored in resfhp could be freed and later dereferenced. We shouldn't call fh_compose() until we
    are certain that we have the final dentry, so this patch moved the fh_compose() call to two places: one
    for the case where the target already exists, and one after dentry_create() where it was created.
    (CVE-2026-89677)

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-2026-89677");
  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:L/AC:L/Au:N/C:P/I:P/A:N");
  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:L/UI:N/S:U/C:N/I:N/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-2026-89677");

  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:"2026/09/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/12");

  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-7.1.13+deb14-alpha-generic"},
          {"reference": "linux-base-7.1.13+deb14-alpha-smp"},
          {"reference": "linux-base-7.1.13+deb14-amd64"},
          {"reference": "linux-base-7.1.13+deb14-arm64"},
          {"reference": "linux-base-7.1.13+deb14-arm64-16k"},
          {"reference": "linux-base-7.1.13+deb14-armmp"},
          {"reference": "linux-base-7.1.13+deb14-armmp-lpae"},
          {"reference": "linux-base-7.1.13+deb14-cloud-amd64"},
          {"reference": "linux-base-7.1.13+deb14-cloud-arm64"},
          {"reference": "linux-base-7.1.13+deb14-loong64"},
          {"reference": "linux-base-7.1.13+deb14-m68k"},
          {"reference": "linux-base-7.1.13+deb14-parisc"},
          {"reference": "linux-base-7.1.13+deb14-parisc64"},
          {"reference": "linux-base-7.1.13+deb14-powerpc"},
          {"reference": "linux-base-7.1.13+deb14-powerpc-smp"},
          {"reference": "linux-base-7.1.13+deb14-powerpc64"},
          {"reference": "linux-base-7.1.13+deb14-powerpc64-64k"},
          {"reference": "linux-base-7.1.13+deb14-powerpc64le"},
          {"reference": "linux-base-7.1.13+deb14-powerpc64le-64k"},
          {"reference": "linux-base-7.1.13+deb14-riscv64"},
          {"reference": "linux-base-7.1.13+deb14-rt-amd64"},
          {"reference": "linux-base-7.1.13+deb14-rt-arm64"},
          {"reference": "linux-base-7.1.13+deb14-s390x"},
          {"reference": "linux-base-7.1.13+deb14-sh7751r"},
          {"reference": "linux-base-7.1.13+deb14-sparc64"},
          {"reference": "linux-base-7.1.13+deb14-sparc64-smp"}
        ]
      }
    ]
  }
};

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');
}