8.8

CVE-2026-43334: Bluetooth: SMP: force responder MITM requirements before building the pairing response

Modified
AliasesUBUNTU-CVE-2026-43334DEBIAN-CVE-2026-43334
Published 08-05-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-43334 is a high (CVSS 8.8) Incorrect Authorization vulnerability in linux. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 20.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.8, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.28%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 39 · Related 35
OPENSUSE-SU-2026:21555-1RHSA-2026:65334RHSA-2026:67150RHSA-2026:70402RHSA-2026:70403SUSE-SU-2026:2195-1

Timeline

  1. 08-05-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

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 metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 0.25% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < 425a22c5373d4e1b46492ab869074ebeeade61f3 | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < 7ab69426e7ecbd18a222ee2ec87ca612d30197d7 | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < 01bb4045d2306c266178f49ce0c3576d237a3040 | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < 91649c02c1baaa18cedf7fb425fa1f0f852c8183 | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < c8ff0ca6508535bccabd81c5c9dcc63de8a3d4fb | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < fa14e0e19820b1bbdb42185c9c4efa950bcffef9 | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < ec17efb1ef91506cfd17a77692eaf4bbacb520ea | ≥ 2b64d153a0cc9d2b60e47be013cde8490f16e0a5, < d05111bfe37bfd8bd4d2dfe6675d6bdeef43f7c7 | 3.3
  • linux_kernel≥ 3.3, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.134 | ≥ 6.7, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.12-1

3 vendors · 160 products

References

39 links
Show all 39 references