CVE-2026-53209: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 6.1.142, before 6.1.176 (fixed in 6.1.176); from 6.6.94, before 6.6.143 (fixed in 6.6.143); from 6.12.34, before 6.12.94 (fixed in 6.12.94); from 6.15.3, before 6.16 (fixed in 6.16); from 6.16.1, before 6.18.36 (fixed in 6.18.36); from 6.19, before 7.0.13 (fixed in 7.0.13); …

Published 2026-06-25. Last modified 2026-07-02.