CVE-2026-63974
Description
A flaw was found in the Bluetooth hci_sync component of the Linux kernel. When the hci_dev_close_sync() function is called during a device reset, the system may experience queuing timeouts. This occurs because the HCI_CMD_DRAIN_WORKQUEUE flag is not properly set, which can lead to system instability or a denial of service (DoS) condition.
Mitigation
To mitigate this issue, disable the Bluetooth service if it is not required.
To disable the Bluetooth service:
`sudo systemctl stop bluetooth`
`sudo systemctl disable bluetooth`
Alternatively, prevent the `bluetooth` kernel module from loading by creating a file `/etc/modprobe.d/bluetooth.conf` with the content `blacklist bluetooth`. Then, regenerate the initramfs using `sudo dracut -f -v`. A system reboot is required for the module blacklisting to take effect. Disabling Bluetooth may impact functionality that relies on Bluetooth connectivity.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | 8.8 |
| Attack Vector | Adjacent Network | N/A | Adjacent Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The main problem is that -- if a lock is overcome -- data could be altered in a bad state.
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