CVE-2026-74534

Bluetooth: ISO: fix refcounting of iso_conn

HIGH
8.8
CVSS Score
Published: August 15, 2026 at 12:27 PM UTC
Updated: October 23, 2026 at 09:17 AM 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 refcounting of iso_conn iso_conn_del() and iso_chan_del() have a race that results to double-put of iso_conn: [Task hdev->workqueue] [Task 2] iso_conn_del iso_chan_del iso_conn_hold_unless_zero iso_conn_lock iso_conn_lock conn->sk = NULL iso_conn_unlock sk = iso_sock_hold(conn) <---------´ if (!sk) iso_conn_put iso_conn_put iso_conn_put /* UAF */ The extra put for !sk in iso_conn_del() is currently required since failing iso_chan_add() may leave iso_conn not associated with any sk. Fix by having iso_pi(sk)->conn own refcount when non-NULL, so iso_conn_del does not need to put it. Adjust the iso_conn_add() refcounting so that conn is put if it does not get associated with an sk.

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 3b921533e8aa95b77aadcf31737595578e735f3c (fixed)
Vendor states this is fixed in 8208b4939afb0a1977fffe902c3ca42fe0f3baaa (fixed)
Vendor states this is fixed in fdfde532ab1caa165fcd8985001157ac8b4db365 (fixed)
Affected range stops below 6.12, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 6.12.113 (unaffected)
Vendor states this is fixed in 6.13 (unaffected)
Vendor states this is fixed in 6.18.44 (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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