CVE-2026-53209
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk4th percentile — higher than 4% of all known CVEs
Summary
A vulnerability was found in the Linux kernel's Bluetooth stack where hci_adv_bcast_annoucement() can cause a temporary buffer overflow when preparing Broadcast Announcement data. The issue occurs when existing advertising instances already hold the maximum extended advertising payload, and prepending service data exceeds the buffer capacity.
Risk Assessment
An attacker could exploit this vulnerability to cause a kernel panic or potentially execute arbitrary code in kernel context, leading to full system compromise.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit 5e7b5d4f3c2a). If an update is not possible, temporarily disable the Broadcast Announcement feature in the Bluetooth driver.
Original NVD description (English source)
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.