Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5 hci_core hci_queue_iso use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k1.36

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5. This affects the function hci_queue_iso of the component hci_core. The manipulation results in use after free. This vulnerability is reported as CVE-2026-98733. The attack can be launched remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5. It has been classified as very critical. Affected is the function hci_queue_iso of the component hci_core. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Serialize fragmented ISO packet queueing The fragmented path in hci_queue_iso() calls __skb_queue_tail() without holding conn->data_q.lock. The socket lock serializes senders, but the transmit worker can concurrently remove packets from this queue using skb_dequeue(). After an insertion saves the old tail pointer, hci_sched_iso() can dequeue that packet and pass it to the driver. The driver can free the packet before the insertion resumes and writes to the old tail's next pointer, causing a use-after-free. Concurrent updates can also corrupt the queue. KASAN reported: BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10 Call Trace: hci_send_iso+0xc7d/0xe10 iso_sock_sendmsg+0x710/0x900 __sys_sendto+0x34a/0x3a0 Allocated by task 86: __alloc_skb+0xdd/0x820 alloc_skb_with_frags+0x7e/0x770 sock_alloc_send_pskb+0x67a/0x820 bt_skb_sendmsg.constprop.0+0xc0/0x6c0 iso_sock_sendmsg+0x44e/0x900 Freed by task 90: kmem_cache_free+0xcb/0x3d0 vhci_read+0x33f/0x4d0 vfs_read+0x177/0xa20 Hold the queue lock across the entire fragment batch, as hci_queue_acl() does, to serialize insertion against dequeue while preserving fragment ordering.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98733 since 09/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 10/18/2026).

Upgrading to version 6.12.113, 6.18.56, 7.2.10 or 7.3-rc6 eliminates this vulnerability. Applying the patch d6d709981208567868c5c01ebd1bec5e5e7fdab0/708cdd203d0bbcf9255fffb2e4c308d5b28851a7/a7161730a3ab3f0a3896000db7ab0284683936e6/1a572db43c057566771b485598ad2e66cb390821 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.113/6.18.56/7.2.10/7.3-rc6
Patch: d6d709981208567868c5c01ebd1bec5e5e7fdab0/708cdd203d0bbcf9255fffb2e4c308d5b28851a7/a7161730a3ab3f0a3896000db7ab0284683936e6/1a572db43c057566771b485598ad2e66cb390821

Timelineinfo

09/25/2026 CVE reserved
10/18/2026 +23 days Advisory disclosed
10/18/2026 +0 days VulDB entry created
10/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98733 (🔒)
GCVE (CVE): GCVE-0-2026-98733
GCVE (VulDB): GCVE-100-421962

Entryinfo

Created: 10/18/2026 19:31
Changes: 10/18/2026 19:31 (59)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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