CVE-2026-46138

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: Fix OOB read and infinite loop in hci_le_create_big_complete_evt hci_le_create_big_complete_evt() iterates over BT_BOUND connections for a BIG handle using a while loop, accessing ev->bis_handle[i++] on each iteration. However, there is no check that i stays within ev->num_bis before the array access. When a controller sends a LE_Create_BIG_Complete event with fewer bis_handle entries than there are BT_BOUND connections for that BIG, or with num_bis=0, the loop reads beyond the valid bis_handle[] flex array into adjacent heap memory. Since the out-of-bounds values typically exceed HCI_CONN_HANDLE_MAX (0x0EFF), hci_conn_set_handle() rejects them and the connection remains in BT_BOUND state. The same connection is then found again by hci_conn_hash_lookup_big_state(), creating an infinite loop with hci_dev_lock held. Fix this by terminating the BIG if in case not all BIS could be setup properly.

CVSS v3.1 Score

8.1

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS — Exploit Prediction

0.0028

Probability of exploitation

0.20%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/22559ad7654f61727fc270ee4893da9f4b70cf17 https://git.kernel.org/stable/c/5ddb8014261137cadaf83ab5617a588d80a22586 https://git.kernel.org/stable/c/665da0baaf0396f9ed3c86ccb3955dcd0b73e774 https://git.kernel.org/stable/c/6cb7f67bc28da787499291a562d49a084d9c90cd https://git.kernel.org/stable/c/77981a507aa0fc001dc37f0dd6631dd2042fed17

Frequently Asked Questions

What is CVE-2026-46138? +

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: Fix OOB read and infinite loop in hci_le_create_big_complete_evt hci_le_create_big_complete_evt() iterates over BT_BOUND connections for a BIG handle using a while loop, accessing ev->bis_handle[i++] on each iteration. However, there is no check that i stays within ev->num_bis before the array access. When a controller sends a LE_Create_BIG_Complete event with fewer bis_handle entries than there are BT_BOUND connections for that BIG, or with num_bis=0, the loop reads beyond the valid bis_handle[] flex array into adjacent heap memory. Since the out-of-bounds values typically exceed HCI_CONN_HANDLE_MAX (0x0EFF), hci_conn_set_handle() rejects them and the connection remains in BT_BOUND state. The same connection is then found again by hci_conn_hash_lookup_big_state(), creating an infinite loop with hci_dev_lock held. Fix this by terminating the BIG if in case not all BIS could be setup properly. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-46138? +

CVE-2026-46138 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0028, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-46138? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.