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NVD / CVE Program· CNA Linux

CVE-2025-39983: Bluetooth: hci_event: Fix UAF in hci_conn_tx_dequeue

Noroxi assessment

Priority: Monitor (action score 35/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2e128683176a56459cef8705fc7c35f438f88abd, dde33124f17cf3bab4dc5e18d1b4dee128361061.

Low priority for now. Upgrade to Linux Linux 2e128683176a56459cef8705fc7c35f438f88abd, dde33124f17cf3bab4dc5e18d1b4dee128361061 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: Fix UAF in hci_conn_tx_dequeue This fixes the following UAF caused by not properly locking hdev when processing HCI_EV_NUM_COMP_PKTS: BUG: KASAN: slab-use-after-free in hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036 Read of size 4 at addr ffff8880740f0940 by task kworker/u11:0/54 CPU: 1 UID: 0 PID: 54 Comm: kworker/u11:0 Not tainted 6.16.0-rc7 #3 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: hci1 hci_rx_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036 hci_num_comp_pkts_evt+0x1c8/0xa50 net/bluetooth/hci_event.c:4404 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 54: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939 le_conn_complete_evt+0x3d6/0x1220 net/bluetooth/hci_event.c:5628 hci_le_enh_conn_complete_evt+0x189/0x470 net/bluetooth/hci_event.c:5794 hci_event_func net/bluetooth/hci_event.c:7474 [inline] hci_event_packet+0x78c/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Freed by task 9572: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 device_release+0x9c/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline] hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173 hci_abort_conn_sync+0x5d1/0xdf0 net/bluetooth/hci_sync.c:5689 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Oct 15, 2025
Updated
Oct 19, 2026
EPSS
0.2% · 16th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CNA vs NVD score

NVD
—
CNA · Linux
8.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.15affected
    • 134f4b39df7b77225a80ef585c15d46f964f5e6f and later · before dde33124f17cf3bab4dc5e18d1b4dee128361061affected · git
    • 134f4b39df7b77225a80ef585c15d46f964f5e6f and later · before 2e128683176a56459cef8705fc7c35f438f88abdaffected · git
    • before 6.15not affected · semver
    • 6.16.10 and later · up to and including 6.16.*not affected · semver
    • 6.17 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.20.1.el10_16.12.0-124.20.1.el10_1
AlmaLinux:10kernel-docbefore 6.12.0-124.20.1.el10_16.12.0-124.20.1.el10_1
Debian:14linuxbefore 6.16.10-16.16.10-1
Red Hat:enterprise_linux_eus:10.0kernelbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64kbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debugbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-debuginfobefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-develbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-devel-matchedbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modulesbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modules-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modules-extrabefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debuginfobefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-develbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-devel-matchedbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modulesbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modules-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modules-extrabefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-abi-stablelistsbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-debugbefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-debug-corebefore 0:6.12.0-55.52.1.el10_00:6.12.0-55.52.1.el10_0

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-39981Oct 15, 2025 · Bluetooth: MGMT: Fix possible UAFs
    31Monitor
  • ← EarlierCVE-2025-39982Oct 15, 2025 · Bluetooth: hci_event: Fix UAF in hci_acl_create_conn_sync
    35Monitor
  • Later →CVE-2025-39984Oct 15, 2025 · net: tun: Update napi->skb after XDP process
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2e128683176a56459cef8705fc7c35f438f88abdVendor (CNA)
Linux Linuxdde33124f17cf3bab4dc5e18d1b4dee128361061Vendor (CNA)
almalinux:kernel-abi-stablelists6.12.0-124.20.1.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-doc6.12.0-124.20.1.el10_1 · AlmaLinux:10Package registry (OSV)
debian:linux6.16.10-1 · Debian:14Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:5.14.0-611.8.1.el9_7 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:kernel0:6.12.0-124.20.1.el10_1 · Rocky Linux:10Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records