Linux Distros Unpatched Vulnerability : CVE-2026-68096

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

include('compat.inc');

if (description)
{
  script_id(334245);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/10");

  script_cve_id("CVE-2026-68096");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-68096");

  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.

  - audit: fix recursive locking deadlock in audit_dupe_exe() A deadlock occurs in the audit subsystem when
    duplicating executable-related rules. When a file is moved (e.g., via do_renameat2()), the VFS layer locks
    the parent directory (I_MUTEX_PARENT), which synchronously triggers an fsnotify_move event. If an existing
    executable audit rule matches the file being moved, the audit subsystem catches this event and calls
    audit_dupe_exe() to duplicate the watch and update the rule. Then, audit_alloc_mark() would call
    kern_path_parent() to resolve the path, leading to a blind attempt to acquire the exact same
    I_MUTEX_PARENT lock already held by the task, resulting in the following recursive locking deadlock:
    ============================================ WARNING: possible recursive locking detected
    6.12.0-55.27.1.el10_0.x86_64+debug #1 Not tainted -------------------------------------------- mv/5099 is
    trying to acquire lock: ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3}, at:
    __kern_path_locked+0x10a/0x2f0 but task is already holding lock: ffff888132846b58
    (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3}, at: lock_two_directories+0x13f/0x2b0 other info
    that might help us debug this: Possible unsafe locking scenario: CPU0 ----
    lock(&inode->i_sb->s_type->i_mutex_dir_key/1); lock(&inode->i_sb->s_type->i_mutex_dir_key/1); *** DEADLOCK
    *** May be due to missing lock nesting notation 6 locks held by mv/5099: #0: ffff888112a9c440
    (sb_writers#13) at: do_renameat2+0x34c/0xbc0 #1: ffff888112a9c790 (&type->s_vfs_rename_key#3) at:
    do_renameat2+0x415/0xbc0 #2: ffff888132846b58 (&inode->i_sb->s_type->i_mutex_dir_key/1) at:
    lock_two_directories+0x13f/0x2b0 #3: ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/5) at:
    lock_two_directories+0x175/0x2b0 #4: ffffffffb3a1fb10 (&fsnotify_mark_srcu) at: fsnotify+0x454/0x28a0 #5:
    ffffffffaf886230 (audit_filter_mutex) at: audit_update_watch+0x36/0x11e0 stack backtrace: Call Trace:
    <TASK> dump_stack_lvl+0x6f/0xb0 print_deadlock_bug.cold+0xbd/0xca validate_chain+0x83a/0xf00
    __lock_acquire+0xcac/0x1d20 lock_acquire.part.0+0x11b/0x360 down_write_nested+0x9f/0x230
    __kern_path_locked+0x10a/0x2f0 kern_path_locked+0x26/0x40 audit_alloc_mark+0xfb/0x4f0
    audit_dupe_exe+0x6c/0xe0 audit_dupe_rule+0x6c2/0xc00 audit_update_watch+0x4cc/0x11e0
    audit_watch_handle_event+0x12c/0x1b0 send_to_group+0x5d0/0x8b0 fsnotify+0x615/0x28a0
    fsnotify_move+0x1d8/0x630 vfs_rename+0xdcd/0x1df0 do_renameat2+0x9d4/0xbc0 __x64_sys_renameat+0x192/0x260
    do_syscall_64+0x92/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0491fe8c4e Code: 0f 1f 40
    00 48 8b 15 c1 e1 16 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 49 89 ca b8 08 01
    00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 89 RSP: 002b:00007ffc7210bf38
    EFLAGS: 00000246 ORIG_RAX: 0000000000000108 RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
    00007f0491fe8c4e RDX: 0000000000000003 RSI: 00007ffc7210e6c8 RDI: 00000000ffffff9c RBP: 0000000000000000
    R08: 0000000000000000 R09: 0000000000000001 R10: 00005575eb2dae2a R11: 0000000000000246 R12:
    00005575eb2dae2a R13: 00007ffc7210e6c8 R14: 0000000000000003 R15: 00000000ffffff9c </TASK> The
    aforementioned deadlock can be consistently reproduced by running the script below: audit-dupe-exe-
    deadlock.sh -------------------------- #!/bin/bash auditctl -D mkdir -p /tmp/foo touch /tmp/file auditctl
    -a always,exit -F exe=/tmp/file -F path=/tmp/file -S all -k dr mv /tmp/file /tmp/foo/file rm -Rf /tmp/foo
    This patch fixes the issue by introducing struct audit_watch_ctx to pass the fsnotify event context down
    to audit_alloc_mark(). By utilizing the already-resolved directory inode provided by the event, we bypass
    the kern_path_parent() path resol ---truncated--- (CVE-2026-68096)

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-2026-68096");
  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-2026-68096");

  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:"2026/08/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  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-11", "Host/OS/Debian Linux-12");

  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-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "bpftool"},
          {"reference": "btrfs-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "cdrom-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "hyperv-daemons"},
          {"reference": "kernel-image-5.10.0-32-alpha-generic-di"},
          {"reference": "libcpupower-dev"},
          {"reference": "libcpupower1"},
          {"reference": "linux-bootwrapper-5.10.0"},
          {"reference": "linux-config-5.10"},
          {"reference": "linux-cpupower"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-5.10"},
          {"reference": "linux-headers-5.10.0"},
          {"reference": "linux-kbuild-5.10"},
          {"reference": "linux-libc-dev"},
          {"reference": "linux-perf"},
          {"reference": "linux-perf-5.10"},
          {"reference": "linux-source"},
          {"reference": "linux-source-5.10"},
          {"reference": "linux-support-5.10.0"},
          {"reference": "loop-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-shared-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-wireless-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "pata-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "ppp-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usb-serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usbip"}
        ]
      }
    ]
  }
};

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');
}