CVE-2026-53209

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sync: reject oversized Broadcast Announcement prepend

Existing advertising instances can already hold the maximum extended

advertising payload. When hci_adv_bcast_annoucement() prepends the

Broadcast Announcement service data to that payload, the combined data

may no longer fit in the temporary buffer used to rebuild the

advertising data.

Reject that case before copying the existing payload and report the

failure through the device log. This keeps the existing advertising

data intact and avoids overrunning the temporary buffer.