Linux Distros Unpatched Vulnerability : CVE-2026-78408

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

include('compat.inc');

if (description)
{
  script_id(342439);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/03");

  script_cve_id("CVE-2026-78408");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-78408");

  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.

  - The nsenter --join-cgroup option opens the target cgroup.procs file as root and leaves that file
    descriptor open across later namespace and credential changes and across execve(). Because the kernel
    checks later cgroup migrations using the credentials from the original open, a program run in an attacker-
    controlled target can inherit root's ability to move host processes between cgroups. After a privileged
    operator uses --join-cgroup against that target, an unprivileged user can migrate and terminate unrelated
    root processes. (CVE-2026-78408)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-78408");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-78408");
  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:C/I:C/A:C");
  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: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-2026-78408");

  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:"2026/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/02");

  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:13.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:util-linux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libblkid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libblkid-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libfdisk");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libfdisk-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libmount");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libmount-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libsmartcols");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libsmartcols-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libuuid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libuuid-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python3-libmount");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:util-linux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:util-linux-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:uuidd");
  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-13", "Host/OS/Debian Linux-14", "Host/OS/Red Hat Enterprise Linux-10");

  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")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) 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": "bsdextrautils"},
          {"reference": "bsdutils"},
          {"reference": "eject"},
          {"reference": "eject-udeb"},
          {"reference": "fdisk"},
          {"reference": "fdisk-udeb"},
          {"reference": "libblkid-dev"},
          {"reference": "libblkid1"},
          {"reference": "libblkid1-udeb"},
          {"reference": "libfdisk-dev"},
          {"reference": "libfdisk1"},
          {"reference": "libfdisk1-udeb"},
          {"reference": "libmount-dev"},
          {"reference": "libmount1"},
          {"reference": "libmount1-udeb"},
          {"reference": "libsmartcols-dev"},
          {"reference": "libsmartcols1"},
          {"reference": "libsmartcols1-udeb"},
          {"reference": "libuuid1"},
          {"reference": "libuuid1-udeb"},
          {"reference": "mount"},
          {"reference": "rfkill"},
          {"reference": "util-linux"},
          {"reference": "util-linux-extra"},
          {"reference": "util-linux-locales"},
          {"reference": "util-linux-udeb"},
          {"reference": "uuid-dev"},
          {"reference": "uuid-runtime"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "bsdextrautils"},
          {"reference": "bsdutils"},
          {"reference": "eject"},
          {"reference": "eject-udeb"},
          {"reference": "fdisk"},
          {"reference": "fdisk-udeb"},
          {"reference": "lastlog2"},
          {"reference": "libblkid-dev"},
          {"reference": "libblkid1"},
          {"reference": "libblkid1-udeb"},
          {"reference": "libfdisk-dev"},
          {"reference": "libfdisk1"},
          {"reference": "libfdisk1-udeb"},
          {"reference": "liblastlog2-2"},
          {"reference": "liblastlog2-dev"},
          {"reference": "libmount-dev"},
          {"reference": "libmount1"},
          {"reference": "libmount1-udeb"},
          {"reference": "libpam-lastlog2"},
          {"reference": "libsmartcols-dev"},
          {"reference": "libsmartcols1"},
          {"reference": "libsmartcols1-udeb"},
          {"reference": "libuuid1"},
          {"reference": "libuuid1-udeb"},
          {"reference": "login"},
          {"reference": "mount"},
          {"reference": "rfkill"},
          {"reference": "util-linux"},
          {"reference": "util-linux-extra"},
          {"reference": "util-linux-locales"},
          {"reference": "util-linux-udeb"},
          {"reference": "uuid-dev"},
          {"reference": "uuid-runtime"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "bsdextrautils"},
          {"reference": "bsdutils"},
          {"reference": "eject"},
          {"reference": "eject-udeb"},
          {"reference": "fdisk"},
          {"reference": "fdisk-udeb"},
          {"reference": "lastlog2"},
          {"reference": "libblkid-dev"},
          {"reference": "libblkid1"},
          {"reference": "libblkid1-udeb"},
          {"reference": "libfdisk-dev"},
          {"reference": "libfdisk1"},
          {"reference": "libfdisk1-udeb"},
          {"reference": "liblastlog2-2"},
          {"reference": "liblastlog2-dev"},
          {"reference": "libmount-dev"},
          {"reference": "libmount1"},
          {"reference": "libmount1-udeb"},
          {"reference": "libpam-lastlog2"},
          {"reference": "libsmartcols-dev"},
          {"reference": "libsmartcols1"},
          {"reference": "libsmartcols1-udeb"},
          {"reference": "libuuid1"},
          {"reference": "libuuid1-udeb"},
          {"reference": "login"},
          {"reference": "mount"},
          {"reference": "rfkill"},
          {"reference": "util-linux"},
          {"reference": "util-linux-extra"},
          {"reference": "util-linux-locales"},
          {"reference": "util-linux-udeb"},
          {"reference": "uuid-dev"},
          {"reference": "uuid-runtime"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "libblkid"},
          {"reference": "libblkid-devel"},
          {"reference": "libfdisk"},
          {"reference": "libfdisk-devel"},
          {"reference": "libmount"},
          {"reference": "libmount-devel"},
          {"reference": "libsmartcols"},
          {"reference": "libsmartcols-devel"},
          {"reference": "libuuid"},
          {"reference": "libuuid-devel"},
          {"reference": "python3-libmount"},
          {"reference": "util-linux"},
          {"reference": "util-linux-core"},
          {"reference": "uuidd"}
        ]
      }
    ]
  }
};

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_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}