CVE-2026-90256: Linux

High severity, CVSS 8.8. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via hci_conn_timeout (disc_work) -> hci_proto_disconn_ind -> l2cap_disconn_ind. This is UAF if the l2cap_conn is deleted concurrently. disc_work is disabled sync in hci_conn_del(), so we cannot take hci_dev_lock in disc_work. Fix by using proto_lock to guard l2cap_data, in addition to hdev->lock which is held in other access paths.

Affected products

• Linux Linux: from 6.6.84, before 6.7 (fixed in 6.7); from 6.12.20, before 6.13 (fixed in 6.13); from 6.13.8, before 6.14 (fixed in 6.14); from 6.14, before 7.2.6 (fixed in 7.2.6)

Published 2026-09-17. Last modified 2026-09-18.