CVE-2026-46186: Bluetooth: virtio_bt: validate rx pkt_type header length

Published May 28, 2026
·
Updated

Bluetooth: virtiobt: validate rx pkttype header length

Affected Software

17 affected componentsFixes available
Linux Linux kernel (virtio_bt)
Linux Linux kernel>=5.15.78<5.15.209
Linux Linux kernel>=6.0.8<6.1
Linux Linux kernel>=6.1.1<6.1.175
Linux Linux kernel>=6.2<6.6.140
Linux Linux kernel>=6.7<6.12.88
Linux Linux kernel>=6.13<6.18.30
Linux Linux kernel>=6.19<7.0.7
Linux Linux kernel=6.1
Linux Linux kernel=6.1-rc4
Linux Linux kernel=6.1-rc5
Linux Linux kernel=6.1-rc6
Linux Linux kernel=6.1-rc7
Linux Linux kernel=6.1-rc8
Linux Linux kernel=7.1-rc1
Linux Linux kernel=7.1-rc2
Microsoft azl3 kernel 6.6.139.1-1<6.6.141.1-1
6.6.141.1-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.141.1-1

Event History

May 28, 2026
CVE Published
via MITRE·09:36 AM
Data Sourced
via MITRE·09:36 AM
Description
Data Sourced
via NVD·10:16 AM
RemedyDescriptionSeverityWeaknessAffected Software
May 29, 2026
Data Sourced
via Microsoft·08:02 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·08:02 AM
Affected Software
Updated
via Microsoft·08:02 AM
DescriptionSeverity

Frequently Asked Questions

1

What input is needed to trigger the vulnerable receive path?

The virtio Bluetooth backend must supply a received buffer containing a packet-type byte but too little remaining data for that packet type's fixed HCI header. A one-byte completion can reach the HCI core after the packet-type byte is removed.

2

Are only ACL packets affected?

No. The driver accepted multiple event, ACL, SCO, and ISO packet types without verifying that the remaining buffer covered the applicable fixed HCI header. The described uninitialized-data read occurs on the ACL classification path when the HCI device has an active CIS_LINK, BIS_LINK, or PA_LINK connection.

3

What does the fix change?

After stripping the packet-type byte, the driver verifies that the remaining packet length is at least the fixed header size required for the selected packet type before passing the frame to the HCI core.

Contact

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