CVE-2025-40301: Linux

High severity, CVSS 7.6. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: validate skb length for unknown CC opcode In hci_cmd_complete_evt(), if the command complete event has an unknown opcode, we assume the first byte of the remaining skb->data contains the return status. However, parameter data has previously been pulled in hci_event_func(), which may leave the skb empty. If so, using skb->data[0] for the return status uses un-init memory. The fix is to check skb->len before using skb->data.

Affected products

• Linux Linux: from 6.1, before 6.1.159 (fixed in 6.1.159); from 6.2, before 6.6.117 (fixed in 6.6.117); from 6.7, before 6.12.58 (fixed in 6.12.58); from 6.13, before 6.17.8 (fixed in 6.17.8)

Published 2025-12-08. Last modified 2026-07-30.