CVE-2026-74533

Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero

HIGH
8.8
CVSS Score
Published: August 15, 2026 at 12:27 PM UTC
Updated: October 21, 2026 at 01:19 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero hci_conn::iso_data is accessed and modified without lock or RCU. This leads to a race [Task hdev->workqueue] [Task 2] iso_recv iso_conn_put(conn) conn = LOAD hcon->iso_data iso_conn_free(conn) iso_conn_hold_unless_zero(conn) hcon->iso_data = NULL kfree(conn) kref_get_unless_zero(&conn->ref) /* UAF */ and also to races in iso_conn_add() vs. iso_conn_free(). Fix by adding spinlock hci_conn::proto_lock and using it to guard hci_conn::iso_data.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.11.116.12.26.13a58d0f5dac322e16cc75334d000666512341bde5dc26097bdb864a0d5955b9a25e43376ffc1af99bf53e7489273dc2bb307bf50f319b3762d45534f0
Vendor states this is fixed in 876a3e94c70d0859d1dad1c986112d4f0d99eba8 (fixed)
Vendor states this is fixed in af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c (fixed)
Affected range stops below 6.12, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 6.12.114 (unaffected)
Vendor states this is fixed in 6.13 (unaffected)
Vendor states this is fixed in 7.1.8 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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