Vulnerability in Linux

CVE-2026-90256

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (31.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-90256: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

  • Linux — versions 18ab6b6078fa8191ca30a3065d57bf35d5635761, 6.14, efc30877bd4bc85fefe98d80af60fafc86e5775e

References

Frequently asked questions

What is CVE-2026-90256?
CVE-2026-90256 is a high-severity vulnerability in Linux. CVSS score: 8.8/10. Published 2026-09-17.
How severe is CVE-2026-90256?
High severity. CVSS v3 base score is 8.8 out of 10.