CVE-2026-63944
Linux kernel Bluetooth UAF allowing kernel crash or RCE via Bluetooth connections.
Is CVE-2026-63944 being exploited?
Not confirmed. CVE-2026-63944 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 0.32% probability of exploitation in the next 30 days.
How severe is CVE-2026-63944?
CVE-2026-63944 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-2026-63944?
Yes. A fix has been recorded for CVE-2026-63944. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63944 affect?
CVE-2026-63944 affects Linux kernel (Bluetooth hci_sync/hci_le_create_cis_sync), Linux distributions with affected kernels, Android devices using affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63944?
Install vendor kernel updates and reboot affected systems.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Bluetooth use-after-free in kernel may allow remote attacker (via Bluetooth) to crash the kernel, escalate privileges, or achieve kernel RCE.
Patch when possible
- affected>= c09b80be6ffc338634b2f5f8cfa12b6843410834 and < a55618c0f4cead9e59c63f5ee030d393fd70d861
- affected>= c09b80be6ffc338634b2f5f8cfa12b6843410834 and < a921957d39290143629eb38c4f74b9bef8035d0a
- affected>= c09b80be6ffc338634b2f5f8cfa12b6843410834 and < d9019210c8c30d40eb20094274cc647e352f48f7
- affected>= c09b80be6ffc338634b2f5f8cfa12b6843410834 and < 380e67b1794a9a281a0cb592b4e62077fbd0c8ca
- affected>= c09b80be6ffc338634b2f5f8cfa12b6843410834 and < bfea6091e0fffb270c20e74384b660910277eb6c
- affected6.4
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.