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Fencer Vulns
high 8.8

CVE-2023-53673 json

Bluetooth: hci_event: call disconnect callback before deleting conn

published 2025-10-07 13 mo ago modified 2026-08-05 3 mo ago also EUVD-2025-31967

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_event: call disconnect callback before deleting conn

In hci_cs_disconnect, we do hci_conn_del even if disconnection failed.

ISO, L2CAP and SCO connections refer to the hci_conn without hci_conn_get, so disconn_cfm must be called so they can clean up their conn, otherwise use-after-free occurs.

ISO: ========================================================== iso_sock_connect:880: sk 00000000eabd6557 iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da ... iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073 hci_dev_put:1487: hci0 orig refcnt 17 __iso_chan_add:214: conn 00000000b6251073 iso_sock_clear_timer:117: sock 00000000eabd6557 state 3 ... hci_rx_work:4085: hci0 Event packet hci_event_packet:7601: hci0: event 0x0f hci_cmd_status_evt:4346: hci0: opcode 0x0406 hci_cs_disconnect:2760: hci0: status 0x0c hci_sent_cmd_data:3107: hci0 opcode 0x0406 hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560 hci_conn_unlink:1102: hci0: hcon 000000001696f1fd hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2 hci_chan_list_flush:2780: hcon 000000001696f1fd hci_dev_put:1487: hci0 orig refcnt 21 hci_dev_put:1487: hci0 orig refcnt 20 hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c ... <no iso_* activity on sk/conn> ... iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557 BUG: kernel NULL pointer dereference, address: 0000000000000668 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth ==========================================================

L2CAP: ================================================================== hci_cmd_status_evt:4359: hci0: opcode 0x0406 hci_cs_disconnect:2760: hci0: status 0x0c hci_sent_cmd_data:3085: hci0 opcode 0x0406 hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585 hci_conn_unlink:1102: hci0: hcon ffff88800c999000 hci_chan_list_flush:2780: hcon ffff88800c999000 hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280 ... BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth] Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175

CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5b/0x90 print_report+0xcf/0x670 ? __virt_addr_valid+0xf8/0x180 ? hci_send_acl+0x2d/0x540 [bluetooth] kasan_report+0xa8/0xe0 ? hci_send_acl+0x2d/0x540 [bluetooth] hci_send_acl+0x2d/0x540 [bluetooth] ? __pfx___lock_acquire+0x10/0x10 l2cap_chan_send+0x1fd/0x1300 [bluetooth] ? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth] ? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth] ? lock_release+0x1d5/0x3c0 ? mark_held_locks+0x1a/0x90 l2cap_sock_sendmsg+0x100/0x170 [bluetooth] sock_write_iter+0x275/0x280 ? __pfx_sock_write_iter+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 do_iter_readv_writev+0x176/0x220 ? __pfx_do_iter_readv_writev+0x10/0x10 ? find_held_lock+0x83/0xa0 ? selinux_file_permission+0x13e/0x210 do_iter_write+0xda/0x340 vfs_writev+0x1b4/0x400 ? __pfx_vfs_writev+0x10/0x10 ? __seccomp_filter+0x112/0x750 ? populate_seccomp_data+0x182/0x220 ? __fget_light+0xdf/0x100 ? do_writev+0x19d/0x210 do_writev+0x19d/0x210 ? __pfx_do_writev+0x10/0x10 ? mark_held_locks+0x1a/0x90 do_syscall_64+0x60/0x90 ? lockdep_hardirqs_on_prepare+0x149/0x210 ? do_syscall_64+0x6c/0x90 ? lockdep_hardirqs_on_prepare+0x149/0x210 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7ff45cb23e64 Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: ---truncated---

Patch / fix

  • Linux Linux 5.15.200, 6.1.42, 6.4.7, 6.5
  • linux Debian 12 6.1.52-1
  • linux Debian 14, Debian 13 6.4.11-1

debian advisories DEBIAN-CVE-2023-53673

  • linux Ubuntu 22.04 LTS 5.15.0-185.195
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1111.118
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1111.121
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1107.113
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1105.109
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1103.108
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1116.125
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1094.102

ubuntu advisories UBUNTU-CVE-2023-53673

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 8 4.18.0-553.97.1.el8_10
  • perf RHEL 8 4.18.0-553.97.1.el8_10
  • bpftool RHEL 8 4.18.0-553.97.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.97.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.97.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.97.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.97.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.97.1.el8_10

red hat advisories RHSA-2026:3360RHSA-2026:2577RHSA-2026:2583RHSA-2026:2573RHSA-2026:2560RHSA-2026:2535

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.127.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.127.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.127.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.127.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.127.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.127.1.150500.6.61.1
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1

suse advisories SUSE-SU-2025:4320-1SUSE-SU-2025:4301-1SUSE-SU-2025:4285-1SUSE-SU-2025:4281-1SUSE-SU-2025:4242-1SUSE-SU-2025:21052-1

  • kernel AlmaLinux 8 4.18.0-553.97.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.97.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.97.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.97.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.97.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.97.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.97.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.97.1.el8_10

almalinux advisories ALSA-2026:1142ALSA-2026:1148

  • kernel-rt Rocky Linux 8 4.18.0-553.97.1.rt7.438.el8_10
  • kernel Rocky Linux 8 4.18.0-553.97.1.el8_10

rocky linux advisories RLSA-2026:1148RLSA-2026:1142

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53673 updated cvss 7.8

kernel: Bluetooth: hci_event: call disconnect callback before deleting conn

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.13.1.el9_4, perf 5.14.0-427.13.1.el9_4, rtla 5.14.0-427.13.1.el9_4, kernel-devel-matched 5.14.0-427.13.1.el9_4, kernel-64k-devel-matched 5.14.0-427.13.1.el9_4, kernel-debug-devel-matched 5.14.0-427.13.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) perf 5.14.0-70.165.1.el9_0, kernel-devel-matched 5.14.0-70.165.1.el9_0, kernel-debug-devel-matched 5.14.0-70.165.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.165.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.165.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.165.1.el9_0, +2 more
    fixed: vendor fix RHSA-2026:2573
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.156.1.el9_2, rtla 5.14.0-284.156.1.el9_2, kernel-devel-matched 5.14.0-284.156.1.el9_2, kernel-64k-devel-matched 5.14.0-284.156.1.el9_2, kernel-debug-devel-matched 5.14.0-284.156.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.156.1.el9_2, +5 more
    fixed: vendor fix RHSA-2026:2560
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.97.1.el8_10, kernel 4.18.0-553.97.1.el8_10, bpftool 4.18.0-553.97.1.el8_10, kernel-core 4.18.0-553.97.1.el8_10, kernel-tools 4.18.0-553.97.1.el8_10, python3-perf 4.18.0-553.97.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:1142
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.13.1.el9_4, kernel 5.14.0-427.13.1.el9_4, kernel-64k 5.14.0-427.13.1.el9_4, kernel-core 5.14.0-427.13.1.el9_4, kernel-tools 5.14.0-427.13.1.el9_4, python3-perf 5.14.0-427.13.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.186.1.el8_4, kernel 4.18.0-305.186.1.el8_4, bpftool 4.18.0-305.186.1.el8_4, kernel-core 4.18.0-305.186.1.el8_4, kernel-tools 4.18.0-305.186.1.el8_4, python3-perf 4.18.0-305.186.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:3360
show 16 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.179.1.el8_6, kernel 4.18.0-372.179.1.el8_6, bpftool 4.18.0-372.179.1.el8_6, kernel-core 4.18.0-372.179.1.el8_6, kernel-tools 4.18.0-372.179.1.el8_6, python3-perf 4.18.0-372.179.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.179.1.el8_6, kernel 4.18.0-372.179.1.el8_6, bpftool 4.18.0-372.179.1.el8_6, kernel-core 4.18.0-372.179.1.el8_6, kernel-tools 4.18.0-372.179.1.el8_6, python3-perf 4.18.0-372.179.1.el8_6, +15 more
    fixed: vendor fix RHSA-2026:2490
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.128.1.el8_8, kernel 4.18.0-477.128.1.el8_8, bpftool 4.18.0-477.128.1.el8_8, kernel-core 4.18.0-477.128.1.el8_8, kernel-tools 4.18.0-477.128.1.el8_8, python3-perf 4.18.0-477.128.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:2535
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) kernel 5.14.0-70.165.1.el9_0, bpftool 5.14.0-70.165.1.el9_0, kernel-core 5.14.0-70.165.1.el9_0, kernel-tools 5.14.0-70.165.1.el9_0, python3-perf 5.14.0-70.165.1.el9_0, kernel-modules 5.14.0-70.165.1.el9_0, +14 more
    fixed: vendor fix RHSA-2026:2573
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.156.1.el9_2, kernel 5.14.0-284.156.1.el9_2, kernel-64k 5.14.0-284.156.1.el9_2, kernel-core 5.14.0-284.156.1.el9_2, kernel-tools 5.14.0-284.156.1.el9_2, python3-perf 5.14.0-284.156.1.el9_2, +28 more
    fixed: vendor fix RHSA-2026:2560
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.186.1.el8_4, kernel 4.18.0-305.186.1.el8_4, bpftool 4.18.0-305.186.1.el8_4, kernel-core 4.18.0-305.186.1.el8_4, kernel-tools 4.18.0-305.186.1.el8_4, python3-perf 4.18.0-305.186.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:3360
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.179.1.el8_6, kernel 4.18.0-372.179.1.el8_6, bpftool 4.18.0-372.179.1.el8_6, kernel-core 4.18.0-372.179.1.el8_6, kernel-tools 4.18.0-372.179.1.el8_6, python3-perf 4.18.0-372.179.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:2490
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.128.1.el8_8, kernel 4.18.0-477.128.1.el8_8, bpftool 4.18.0-477.128.1.el8_8, kernel-core 4.18.0-477.128.1.el8_8, kernel-tools 4.18.0-477.128.1.el8_8, python3-perf 4.18.0-477.128.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:2535
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.97.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.97.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.97.1.el8_10
    fixed: vendor fix RHSA-2026:1142
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.13.1.el9_4
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-kvm 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-core 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-modules 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-debug-kvm 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-debug-core 4.18.0-553.97.1.rt7.438.el8_10, +4 more
    fixed: vendor fix RHSA-2026:1148
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-kvm 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-kvm 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-core 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-modules 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-debug-kvm 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-debug-core 5.14.0-70.165.1.rt21.237.el9_0, +4 more Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-core 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-modules 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-debug-core 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-debug-modules 5.14.0-70.165.1.rt21.237.el9_0, kernel-rt-modules-extra 5.14.0-70.165.1.rt21.237.el9_0, +2 more
    fixed: vendor fix RHSA-2026:2577
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-core 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-modules 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-debug-core 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-modules-core 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-debug-modules 5.14.0-284.156.1.rt14.441.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-kvm 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-core 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-modules 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-debug-kvm 5.14.0-284.156.1.rt14.441.el9_2, kernel-rt-debug-core 5.14.0-284.156.1.rt14.441.el9_2, +6 more
    fixed: vendor fix RHSA-2026:2583
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-core 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-modules 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-debug-core 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-debug-modules 4.18.0-553.97.1.rt7.438.el8_10, kernel-rt-modules-extra 4.18.0-553.97.1.rt7.438.el8_10, +2 more
    fixed: vendor fix RHSA-2026:1148
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, kernel-rt-modules-core 5.14.0-427.13.1.el9_4, kernel-rt-debug-modules 5.14.0-427.13.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.