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Linux CVE-2026-23462

| EUVDEUVD-2026-18724 HIGH
Use After Free (CWE-416)
2026-04-03 Linux GHSA-2m32-7xgm-rmj6
Linux Debian Information Disclosure Memory Corruption Use After Free
8.8
CVSS 3.1 · NVD
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Severity by source

NVD PRIMARY
8.8 HIGH
AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SUSE
HIGH
qualitative
Red Hat
5.5 MEDIUM
qualitative

Primary rating from NVD.

CVSS VectorNVD

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

6
Re-analysis Queued
Apr 27, 2026 - 14:22 vuln.today
cvss_changed
CVSS changed
Apr 27, 2026 - 14:22 NVD
8.8 (HIGH)
Patch available
Apr 16, 2026 - 05:29 EUVD
4d37fa7582aa960ba23e10a7a2596a29f37ad281,7c805b7d1e580eececcc92470292e3dbc42bc3f5,21a47a119f33df9bb157326846390d7e8e1b45ba
EUVD ID Assigned
Apr 03, 2026 - 15:30 euvd
EUVD-2026-18724
Analysis Generated
Apr 03, 2026 - 15:30 vuln.today
CVE Published
Apr 03, 2026 - 15:15 nvd
N/A

DescriptionCVE.org

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

Bluetooth: HIDP: Fix possible UAF

This fixes the following trace caused by not dropping l2cap_conn reference when user->remove callback is called:

[ 97.809249] l2cap_conn_free: freeing conn ffff88810a171c00 [ 97.809907] CPU: 1 UID: 0 PID: 1419 Comm: repro_standalon Not tainted 7.0.0-rc1-dirty #14 PREEMPT(lazy) [ 97.809935] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 97.809947] Call Trace: [ 97.809954] <TASK> [ 97.809961] dump_stack_lvl (lib/dump_stack.c:122) [ 97.809990] l2cap_conn_free (net/bluetooth/l2cap_core.c:1808) [ 97.810017] l2cap_conn_del (./include/linux/kref.h:66 net/bluetooth/l2cap_core.c:1821 net/bluetooth/l2cap_core.c:1798) [ 97.810055] l2cap_disconn_cfm (net/bluetooth/l2cap_core.c:7347 (discriminator 1) net/bluetooth/l2cap_core.c:7340 (discriminator 1)) [ 97.810086] ? __pfx_l2cap_disconn_cfm (net/bluetooth/l2cap_core.c:7341) [ 97.810117] hci_conn_hash_flush (./include/net/bluetooth/hci_core.h:2152 (discriminator 2) net/bluetooth/hci_conn.c:2644 (discriminator 2)) [ 97.810148] hci_dev_close_sync (net/bluetooth/hci_sync.c:5360) [ 97.810180] ? __pfx_hci_dev_close_sync (net/bluetooth/hci_sync.c:5285) [ 97.810212] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810242] ? up_write (./arch/x86/include/asm/atomic64_64.h:87 (discriminator 5) ./include/linux/atomic/atomic-arch-fallback.h:2852 (discriminator 5) ./include/linux/atomic/atomic-long.h:268 (discriminator 5) ./include/linux/atomic/atomic-instrumented.h:3391 (discriminator 5) kernel/locking/rwsem.c:1385 (discriminator 5) kernel/locking/rwsem.c:1643 (discriminator 5)) [ 97.810267] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810290] ? rcu_is_watching (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/context_tracking.h:128 kernel/rcu/tree.c:752) [ 97.810320] hci_unregister_dev (net/bluetooth/hci_core.c:504 net/bluetooth/hci_core.c:2716) [ 97.810346] vhci_release (drivers/bluetooth/hci_vhci.c:691) [ 97.810375] ? __pfx_vhci_release (drivers/bluetooth/hci_vhci.c:678) [ 97.810404] __fput (fs/file_table.c:470) [ 97.810430] task_work_run (kernel/task_work.c:235) [ 97.810451] ? __pfx_task_work_run (kernel/task_work.c:201) [ 97.810472] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810495] ? do_raw_spin_unlock (./include/asm-generic/qspinlock.h:128 (discriminator 5) kernel/locking/spinlock_debug.c:142 (discriminator 5)) [ 97.810527] do_exit (kernel/exit.c:972) [ 97.810547] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810574] ? __pfx_do_exit (kernel/exit.c:897) [ 97.810594] ? lock_acquire (kernel/locking/lockdep.c:470 (discriminator 6) kernel/locking/lockdep.c:5870 (discriminator 6) kernel/locking/lockdep.c:5825 (discriminator 6)) [ 97.810616] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810639] ? do_raw_spin_lock (kernel/locking/spinlock_debug.c:95 (discriminator 4) kernel/locking/spinlock_debug.c:118 (discriminator 4)) [ 97.810664] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810688] ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1)) [ 97.810721] do_group_exit (kernel/exit.c:1093) [ 97.810745] get_signal (kernel/signal.c:3007 (discriminator 1)) [ 97.810772] ? security_file_permission (./arch/x86/include/asm/jump_label.h:37 security/security.c:2366) [ 97.810803] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810826] ? vfs_read (fs/read_write.c:555) [ 97.810854] ? __pfx_get_signal (kernel/signal.c:2800) [ 97.810880] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810905] ? __pfx_vfs_read (fs/read_write.c:555) [ 97.810932] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 97.810960] arch_do_signal_or_restart (arch/ ---truncated---

AnalysisAI

Use-after-free vulnerability in the Linux kernel's Bluetooth HIDP subsystem allows local attackers to trigger a kernel crash or potentially execute arbitrary code by failing to properly release L2CAP connection references when user callbacks are invoked. The flaw affects all Linux kernel versions in the CPE range and has been resolved through reference counting fixes in the L2CAP connection cleanup path; no public exploit code is currently identified, but the vulnerability requires local access to trigger via Bluetooth device manipulation.

Technical ContextAI

The vulnerability exists in the Linux kernel's Bluetooth Human Interface Device Protocol (HIDP) layer, specifically in the interaction between HIDP session management and L2CAP (Logical Link Control and Adaptation Protocol) connection lifecycle. When a HIDP user callback (user->remove) is invoked during device disconnection, the kernel fails to decrement the reference count on the associated L2CAP connection object. This creates a use-after-free condition where the L2CAP connection structure is freed by the reference counting mechanism (kref) while still holding references in the HIDP layer, leading to potential memory corruption. The root cause is improper reference counting discipline in net/bluetooth/hidp/core.c where L2CAP connection references are not properly balanced between acquisition and release points. The call trace shows the crash occurring during HCI device unregistration when L2CAP connections are being flushed, indicating a race condition or improper cleanup ordering.

RemediationAI

Update the Linux kernel to a version incorporating the reference counting fix for HIDP/L2CAP connection cleanup. The upstream patches are available at the Git commit hashes provided: https://git.kernel.org/stable/c/21a47a119f33df9bb157326846390d7e8e1b45ba and related commits (45ebe5b900200ac3e01f3470506a44a447825721, 7c805b7d1e580eececcc92470292e3dbc42bc3f5, f8b6ed2f06d3baa44f347a0fa2af52433f386463, 4d37fa7582aa960ba23e10a7a2596a29f37ad281, dbf666e4fc9bdd975a61bf682b3f75cb0145eedd). Debian and other distribution maintainers should apply these patches to their stable kernel branches. Until patched kernel availability, mitigation options include disabling Bluetooth HIDP support if not required via kernel module blacklisting (adding 'blacklist hidp' to /etc/modprobe.d/blacklist.conf and rebuilding initramfs) or restricting access to Bluetooth device files via user permissions and udev rules.

Same weakness CWE-416 – Use After Free

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Vendor StatusVendor

SUSE

Severity: High
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed

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CVE-2026-23462 vulnerability details – vuln.today
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