CVE-2026-43334

HIGH

Bluetooth: SMP: force responder MITM requirements before building the pairing response

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SMP: force responder MITM requirements before building the pairing response smp_cmd_pairing_req() currently builds the pairing response from the initiator auth_req before enforcing the local BT_SECURITY_HIGH requirement. If the initiator omits SMP_AUTH_MITM, the response can also omit it even though the local side still requires MITM. tk_request() then sees an auth value without SMP_AUTH_MITM and may select JUST_CFM, making method selection inconsistent with the pairing policy the responder already enforces. When the local side requires HIGH security, first verify that MITM can be achieved from the IO capabilities and then force SMP_AUTH_MITM in the response in both rsp.auth_req and auth. This keeps the responder auth bits and later method selection aligned.

Scores

CVSS v3 8.8
EPSS 0.0003
EPSS Percentile 7.5%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

Status published
Products (20)
Linux/Linux < 3.3
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - 01bb4045d2306c266178f49ce0c3576d237a3040
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - 425a22c5373d4e1b46492ab869074ebeeade61f3
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - 7ab69426e7ecbd18a222ee2ec87ca612d30197d7
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - 91649c02c1baaa18cedf7fb425fa1f0f852c8183
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - c8ff0ca6508535bccabd81c5c9dcc63de8a3d4fb
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - d05111bfe37bfd8bd4d2dfe6675d6bdeef43f7c7
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - ec17efb1ef91506cfd17a77692eaf4bbacb520ea
Linux/Linux 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 - fa14e0e19820b1bbdb42185c9c4efa950bcffef9
Linux/Linux 3.3
... and 10 more
Published May 08, 2026
Tracked Since May 08, 2026