Widely used Linux kernel Bluetooth stack; MITM risk in legacy pairing could disrupt devices across industries.
CVE-2026-31773
Linux kernel Bluetooth SMP mislabels STK auth; MITM risk during legacy pairing.
Is CVE-2026-31773 being exploited?
Not confirmed. CVE-2026-31773 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.28% probability of exploitation in the next 30 days.
How severe is CVE-2026-31773?
CVE-2026-31773 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-31773?
Yes. A fix has been recorded for CVE-2026-31773. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-31773 affect?
CVE-2026-31773 affects Linux kernel Bluetooth stack. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-31773?
Patch ASAP and reboot
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
MITM risk during Bluetooth pairing; STK labeled authenticated despite outcome, enabling eavesdropping/tampering in legacy modes.
Immediate action required
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 9a38659a3d06080715691bd3139f9c4b61f688e3
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 667f44f1392df6482483756458c48670e579e9ff
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 929db734d12db41ca5f95424db4612397f1bd4a7
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < b1c6a8e554a39b222c0879a288ea98e338fc4d77
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 0afc846bd80073ffcd2b8040f2b2fafaea3d9f72
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 061ee71ac6b03c9f8432fe49538c3682bfcf4cf3
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 9a6d0db176f082685e0b6149700c0baf3ce2aa8b
- affected>= fff3490f47810e2d34b91fb9e31103e923b11c2f and < 20756fec2f0108cb88e815941f1ffff88dc286fe
- affected14ec593d6bb050cf40a4ade2f9ac9ca050e0412c
- affected>= 3.15.5 and < 3.16
- affected3.16
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.