High severity · published May 8, 2026
CVE-2026-43334
Bluetooth: SMP: force responder MITM requirements before building the pairing response
8.8
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
3.3 before 5.10.253; 5.11 before 5.15.203; 5.16 before 6.1.168; 6.2 before 6.6.134; 6.7 before 6.12.81; 6.13 before 6.18.22; +7 more · source: NVD
LI
Linux · Linux
2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before 425a22c5373d4e1b46492ab869074ebeeade61f3; 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before 7ab69426e7ecbd18a222ee2ec87ca612d30197d7; 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before 01bb4045d2306c266178f49ce0c3576d237a3040; 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before 91649c02c1baaa18cedf7fb425fa1f0f852c8183; 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before c8ff0ca6508535bccabd81c5c9dcc63de8a3d4fb; 2b64d153a0cc9d2b60e47be013cde8490f16e0a5 before fa14e0e19820b1bbdb42185c9c4efa950bcffef9; +3 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-43334
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-43334
Patch
https://git.kernel.org/stable/c/01bb4045d2306c266178f49ce0c3576d237a3040
Patch
https://git.kernel.org/stable/c/425a22c5373d4e1b46492ab869074ebeeade61f3
Patch
https://git.kernel.org/stable/c/7ab69426e7ecbd18a222ee2ec87ca612d30197d7
Patch
https://git.kernel.org/stable/c/91649c02c1baaa18cedf7fb425fa1f0f852c8183
Patch
https://git.kernel.org/stable/c/c8ff0ca6508535bccabd81c5c9dcc63de8a3d4fb
Patch
https://git.kernel.org/stable/c/d05111bfe37bfd8bd4d2dfe6675d6bdeef43f7c7
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