Affects Linux kernel Bluetooth subsystem; potential kernel-level RCE across widely deployed systems.
CVE-2026-31771
Linux kernel Bluetooth HCI event handling may permit RCE via malformed HCI frames.
Is CVE-2026-31771 being exploited?
Not confirmed. CVE-2026-31771 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 0.21% probability of exploitation in the next 30 days.
How severe is CVE-2026-31771?
CVE-2026-31771 is rated High with a CVSS score of 8.1. 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-2026-31771?
Yes. A fix has been recorded for CVE-2026-31771. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-31771 affect?
CVE-2026-31771 affects Linux kernel (Bluetooth subsystem). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-31771?
Upgrade to patched kernel with Bluetooth fixes
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Kernel-level RCE via short Bluetooth HCI frames before event-length validation.
Patch when possible
- affected>= 2f20216c1d6fe17c1a224f658be0dc6fab2269c7 and < 86c8d07a64d553c41e213b52650020010f9ef23e
- affected>= 2f20216c1d6fe17c1a224f658be0dc6fab2269c7 and < 2b2bf47cd75518c36fa2d41380e4a40641cc89cd
- affected5.10
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.