CVE-2026-63974
Linux kernel Bluetooth race can cause device hang/DoS
Is CVE-2026-63974 being exploited?
Not confirmed. CVE-2026-63974 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-2026-63974?
CVE-2026-63974 is rated High. 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-2026-63974?
Yes. A fix has been recorded for CVE-2026-63974. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63974 affect?
CVE-2026-63974 affects Linux kernel (Bluetooth subsystem: hci_sync / hci_dev_close_sync), Devices using affected Linux kernels with Bluetooth. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63974?
Upgrade kernel to patched release or apply vendor Bluetooth kernel patch
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker with Bluetooth access can trigger a workqueue race during device close, causing Bluetooth device hang or kernel-level DoS.
Patch when possible
- affected>= 877afadad2dce8aae1f2aad8ce47e072d4f6165e and < 9cebe4680bb9a72f80c6541eb24af06db7a1fbc9
- affected>= 877afadad2dce8aae1f2aad8ce47e072d4f6165e and < 47330cc875b36a1cf7b3543cb2cf90a7c603ce0e
- affected>= 877afadad2dce8aae1f2aad8ce47e072d4f6165e and < 60bceb9a4c693e68cc90ba4b2dfb9e000e8638ff
- affected>= 877afadad2dce8aae1f2aad8ce47e072d4f6165e and < 525daaea459fc215f432de1b8debbd9144bf97b0
- affected4bf367fa1fefabdf14938d0ac9ed60020389112e
- affected3b382555706558f5c0587862b6dc03e96a252bba
- affected>= 5.18.18 and < 5.19
- affected>= 5.19.2 and < 5.20
- affected6.0
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.