CVE-2026-31773 (GCVE-0-2026-31773)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-05-11 22:15
VLAI?
Title
Bluetooth: SMP: derive legacy responder STK authentication from MITM state
Summary
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.
Severity ?
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 9a38659a3d06080715691bd3139f9c4b61f688e3 (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 667f44f1392df6482483756458c48670e579e9ff (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 929db734d12db41ca5f95424db4612397f1bd4a7 (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < b1c6a8e554a39b222c0879a288ea98e338fc4d77 (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 0afc846bd80073ffcd2b8040f2b2fafaea3d9f72 (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 061ee71ac6b03c9f8432fe49538c3682bfcf4cf3 (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 9a6d0db176f082685e0b6149700c0baf3ce2aa8b (git)
Affected: fff3490f47810e2d34b91fb9e31103e923b11c2f , < 20756fec2f0108cb88e815941f1ffff88dc286fe (git)
Affected: 14ec593d6bb050cf40a4ade2f9ac9ca050e0412c (git)
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Linux Linux Affected: 3.16
Unaffected: 0 , < 3.16 (semver)
Unaffected: 5.10.253 , ≤ 5.10.* (semver)
Unaffected: 5.15.203 , ≤ 5.15.* (semver)
Unaffected: 6.1.168 , ≤ 6.1.* (semver)
Unaffected: 6.6.134 , ≤ 6.6.* (semver)
Unaffected: 6.12.81 , ≤ 6.12.* (semver)
Unaffected: 6.18.22 , ≤ 6.18.* (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.