CVE-2026-31773

high

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SMP: derive legacy responder STK authentication from MITM state The legacy res…

Vendor / product: Linux — linux kernel

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SMP: derive legacy responder STK authentication from MITM state The legacy responder path in smp_random() currently labels the stored STK as authenticated whenever pending_sec_level is BT_SECURITY_HIGH. That reflects what the local service requested, not what the pairing flow actually achieved. For Just Works/Confirm legacy pairing, SMP_FLAG_MITM_AUTH stays clear and the resulting STK should remain unauthenticated even if the local side requested HIGH security. Use the established MITM state when storing the responder STK so the key metadata matches the pairing result. This also keeps the legacy path aligned with the Secure Connections code, which already treats JUST_WORKS/JUST_CFM as unauthenticated.

CVSS

8.8

8.8 (CVSS v3.1)

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity source: NVD CVSS v3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Timeline (UTC)

Published: 2026-05-01 15:16

Modified: 2026-11-11 21:10

NVD status: Modified

Last synced 5 hours ago

Verified against the source API 2026-11-11 21:11 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

linux / linux_kernel ≥3.15.5 <3.16, ≥3.16.1 <5.10.253, ≥5.11 <5.15.203, ≥5.16 <6.1.168, ≥6.2 <6.6.134, ≥6.7 <6.12.81

Weakness classification (CWE)

NVD-CWE-noinfo CWE-287

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Patch / mitigation: https://git.kernel.org/stable/c/061ee71ac6b03c9f8432fe49538c3682bfcf4cf3

Patch / mitigation: https://git.kernel.org/stable/c/0afc846bd80073ffcd2b8040f2b2fafaea3d9f72

Patch / mitigation: https://git.kernel.org/stable/c/20756fec2f0108cb88e815941f1ffff88dc286fe

Patch / mitigation: https://git.kernel.org/stable/c/667f44f1392df6482483756458c48670e579e9ff

Patch / mitigation: https://git.kernel.org/stable/c/929db734d12db41ca5f95424db4612397f1bd4a7

Patch / mitigation: https://git.kernel.org/stable/c/9a38659a3d06080715691bd3139f9c4b61f688e3

Patch / mitigation: https://git.kernel.org/stable/c/9a6d0db176f082685e0b6149700c0baf3ce2aa8b

Patch / mitigation: https://git.kernel.org/stable/c/b1c6a8e554a39b222c0879a288ea98e338fc4d77

References

https://git.kernel.org/stable/c/061ee71ac6b03c9f8432fe49538c3682bfcf4cf3 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0afc846bd80073ffcd2b8040f2b2fafaea3d9f72 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/20756fec2f0108cb88e815941f1ffff88dc286fe 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/667f44f1392df6482483756458c48670e579e9ff 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/929db734d12db41ca5f95424db4612397f1bd4a7 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9a38659a3d06080715691bd3139f9c4b61f688e3 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9a6d0db176f082685e0b6149700c0baf3ce2aa8b 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b1c6a8e554a39b222c0879a288ea98e338fc4d77 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Data sources

NVD CVE API 2.0 — fetched 2026-11-11 21:11 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores

CVE-2026-31773

Affected products

Weakness classification (CWE)

Mitigation & advisories

References

Data sources

Learn the basics

Related CVEs