CVE-2026-23146

Medium

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling hci_uart_register_dev(), which calls proto->open() to initialize hu->priv. However, if a TTY write wakeup occurs during this window, hci_uart_tx_wakeup() may schedule write_work before hu->priv is initialized, leading to a NULL pointer dereference in hci_uart_write_work() when proto->dequeue() accesses hu->priv. The race condition is: CPU0 CPU1 ---- ---- hci_uart_set_proto() set_bit(HCI_UART_PROTO_INIT) hci_uart_register_dev() tty write wakeup hci_uart_tty_wakeup() hci_uart_tx_wakeup() schedule_work(&hu->write_work) proto->open(hu) // initializes hu->priv hci_uart_write_work() hci_uart_dequeue() proto->dequeue(hu) // accesses hu->priv (NULL!) Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open() succeeds, ensuring hu->priv is initialized before any work can be scheduled.

Package Linux Kernel
Published 2026-02-14
Last modified 2026-03-17
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2026-23146 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.10.237, 5.15.181, 6.1.135, 6.6.88, 6.12.24, 5.4.293, 6.13.12, 6.14.3, 6.15 and later are affected. Fixed in 5.10.249, 5.15.199, 6.1.162, 6.6.123, 6.12.69, 6.18.9, 6.19 and their respective stable series.

Affected from
≥ 5.10.237 ≥ 5.15.181 ≥ 6.1.135 ≥ 6.6.88 ≥ 6.12.24 ≥ 5.4.293 ≥ 6.13.12 ≥ 6.14.3 ≥ 6.15
Fixed in
✓ 5.10.249 5.10.x ✓ 5.15.199 5.15.x ✓ 6.1.162 6.1.x ✓ 6.6.123 6.6.x ✓ 6.12.69 6.12.x ✓ 6.18.9 6.18.x ✓ 6.19

References

The following references provide additional information about CVE-2026-23146 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-23146?

    CVE-2026-23146 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.10.237 onward and has been patched in 5.10.249, 5.15.199, 6.1.162 and others. CVE-2026-23146 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-23146?

    CVE-2026-23146 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-23146?

    Yes — CVE-2026-23146 has been patched. Fixed versions include 5.10.249, 5.15.199, 6.1.162 and others. If you are running Linux kernel 5.10.237 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-23146 actively exploited?

    No — CVE-2026-23146 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

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