NVD / CVE Program· CNA Linux

CVE-2025-38250: Bluetooth: hci_core: Fix use-after-free in vhci_flush()

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.18% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 0e5c144c557df910ab64d9c25d06399a9a735e65, 1d6123102e9fbedc8d25bf4731da6d513173e49e, 90dee0a0ff84fac8accd5be98412b3819f667149; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 0e5c144c557df910ab64d9c25d06399a9a735e65, 1d6123102e9fbedc8d25bf4731da6d513173e49e, 90dee0a0ff84fac8accd5be98412b3819f667149; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes 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_core: Fix use-after-free in vhci_flush() syzbot reported use-after-free in vhci_flush() without repro. [0] From the splat, a thread close()d a vhci file descriptor while its device was being used by iotcl() on another thread. Once the last fd refcnt is released, vhci_release() calls hci_unregister_dev(), hci_free_dev(), and kfree() for struct vhci_data, which is set to hci_dev->dev->driver_data. The problem is that there is no synchronisation after unlinking hdev from hci_dev_list in hci_unregister_dev(). There might be another thread still accessing the hdev which was fetched before the unlink operation. We can use SRCU for such synchronisation. Let's run hci_dev_reset() under SRCU and wait for its completion in hci_unregister_dev(). Another option would be to restore hci_dev->destruct(), which was removed in commit 587ae086f6e4 ("Bluetooth: Remove unused hci-destruct cb"). However, this would not be a good solution, as we should not run hci_unregister_dev() while there are in-flight ioctl() requests, which could lead to another data-race KCSAN splat. Note that other drivers seem to have the same problem, for exmaple, virtbt_remove(). [0]: BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718 CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 skb_queue_purge include/linux/skbuff.h:3368 [inline] vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69 hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline] hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf5b98e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929 RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009 RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528 </TASK> Allocated by task 6535: 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] vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635 misc_open+0x2bc/0x330 drivers/char/misc.c:161 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/name ---truncated---

Memory safety

Published: Jul 9, 2025
Updated: Oct 15, 2026
EPSS: 0.1% · 7th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 7.8; agree

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

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

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
- 3.4affected
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before dd4becd3fd4102696e1c15e6d260a1712a2d8685affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before 90dee0a0ff84fac8accd5be98412b3819f667149affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before c56b177efce8b62798e4d96bdb9867106cb7c4a0affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before bc0819a25e04cd68ef3568cfa51b63118fea39a7affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before ce23b73f0f27e2dbeb81734a79db710f05aa33c6affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before 0e5c144c557df910ab64d9c25d06399a9a735e65affected · git
- bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f and later · before 1d6123102e9fbedc8d25bf4731da6d513173e49eaffected · git
- before 3.4not affected · semver
- 5.10.259 and later · up to and including 5.10.*not affected · semver

Affected versions · NVD (4)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel3.4 and later · before 6.6.97
linux linux kernel6.7 and later · before 6.12.36
linux linux kernel6.13 and later · before 6.15.5
linux linux kernel6.16

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
AlmaLinux:10	kernel-abi-stablelists	before 6.12.0-55.28.1.el10_0	6.12.0-55.28.1.el10_0
AlmaLinux:10	kernel-doc	before 6.12.0-55.28.1.el10_0	6.12.0-55.28.1.el10_0
AlmaLinux:8	bpftool	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-abi-stablelists	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-core	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-cross-headers	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-debug	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-debug-core	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-debug-devel	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-debug-modules	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-debug-modules-extra	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-devel	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-doc	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-headers	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-modules	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-modules-extra	before 4.18.0-553.70.1.el8_10	4.18.0-553.70.1.el8_10
AlmaLinux:8	kernel-rt	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-core	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-debug	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-debug-core	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-debug-devel	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-debug-modules	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10
AlmaLinux:8	kernel-rt-debug-modules-extra	before 4.18.0-553.70.1.rt7.411.el8_10	4.18.0-553.70.1.rt7.411.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

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CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2025-38248Jul 9, 2025 · bridge: mcast: Fix use-after-free during router port configuration
31Monitor
← EarlierCVE-2025-38249Jul 9, 2025 · ALSA: usb-audio: Fix out-of-bounds read in snd_usb_get_audioformat_uac3()
28Monitor
Later →CVE-2025-38251Jul 9, 2025 · atm: clip: prevent NULL deref in clip_push()
22Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
Linux Linux	0e5c144c557df910ab64d9c25d06399a9a735e65	Vendor (CNA)
Linux Linux	1d6123102e9fbedc8d25bf4731da6d513173e49e	Vendor (CNA)
Linux Linux	90dee0a0ff84fac8accd5be98412b3819f667149	Vendor (CNA)
Linux Linux	bc0819a25e04cd68ef3568cfa51b63118fea39a7	Vendor (CNA)
Linux Linux	c56b177efce8b62798e4d96bdb9867106cb7c4a0	Vendor (CNA)
Linux Linux	ce23b73f0f27e2dbeb81734a79db710f05aa33c6	Vendor (CNA)
Linux Linux	dd4becd3fd4102696e1c15e6d260a1712a2d8685	Vendor (CNA)
azl3 kernel 6.6.96.2-2 on Azure Linux 3.0	6.6.104.2-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0	Release Notes	Microsoft (MSRC)
almalinux:bpftool	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-abi-stablelists	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-core	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-cross-headers	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-debug	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-debug-core	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-debug-devel	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-debug-modules	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-debug-modules-extra	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-devel	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-doc	4.18.0-553.70.1.el8_10 · AlmaLinux:8	Package registry (OSV)
debian:linux	6.1.170-1 · Debian:12	Package registry (OSV)
opensuse:dtb-aarch64	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-64kb	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-azure	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-default	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-default-base	6.12.0-160000.37.1.160000.2.19 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-docs	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-kvmsmall	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:kernel-obs-build	6.12.0-160000.37.1 · openSUSE:Leap 16.0	Package registry (OSV)

+28

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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
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: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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 (2)

SSVC exploitation— → noneOct 15, 2026, 11:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:08 PM UTC

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

References

git.kernel.org/stable/c/0e5c144c557df910ab64d9c25d06399a9a735e65

Show all references (7 more)

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

All records