# CVE-2026-43449: nvme-pci: Fix slab-out-of-bounds in nvme_dbbuf_set

> A slab-out-of-bounds read in the Linux kernel NVMe driver allows attackers to cause a denial of service or potentially execute code.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 May 2026
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2026-43449, DEBIAN-CVE-2026-43449, GHSA-hv7m-w2x8-mf6q, ROOT-OS-DEBIAN-11-CVE-2026-43449, ROOT-OS-UBUNTU-2204-CVE-2026-43449, ROOT-OS-UBUNTU-2404-CVE-2026-43449, UBUNTU-CVE-2026-43449

## What is CVE-2026-43449?

CVE-2026-43449 is a high-severity memory corruption vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

nvme-pci: Fix slab-out-of-bounds in nvme_dbbuf_set

dev->online_queues is a count incremented in nvme_init_queue. Thus,
valid indices are 0 through dev->online_queues − 1.

This patch fixes the loop condition to ensure the index stays within the
valid range. Index 0 is excluded because it is the admin queue.

KASAN splat:

==================================================================
BUG: KASAN: slab-out-of-bounds in nvme_dbbuf_free drivers/nvme/host/pci.c:377 [inline]
BUG: KASAN: slab-out-of-bounds in nvme_dbbuf_set+0x39c/0x400 drivers/nvme/host/pci.c:404
Read of size 2 at addr ffff88800592a574 by task kworker/u8:5/74

CPU: 0 UID: 0 PID: 74 Comm: kworker/u8:5 Not tainted 6.19.0-dirty #10 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: nvme-reset-wq nvme_reset_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xea/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xce/0x5d0 mm/kasan/report.c:482
 kasan_report+0xdc/0x110 mm/kasan/report.c:595
 __asan_report_load2_noabort+0x18/0x20 mm/kasan/report_generic.c:379
 nvme_dbbuf_free drivers/nvme/host/pci.c:377 [inline]
 nvme_dbbuf_set+0x39c/0x400 drivers/nvme/host/pci.c:404
 nvme_reset_work+0x36b/0x8c0 drivers/nvme/host/pci.c:3252
 process_one_work+0x956/0x1aa0 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x65c/0xe60 kernel/workqueue.c:3421
 kthread+0x41a/0x930 kernel/kthread.c:463
 ret_from_fork+0x6f8/0x8c0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 34 on cpu 1 at 4.241550s:
 kasan_save_stack+0x2c/0x60 mm/kasan/common.c:57
 kasan_save_track+0x1c/0x70 mm/kasan/common.c:78
 kasan_save_alloc_info+0x3c/0x50 mm/kasan/generic.c:570
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xb5/0xc0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kmalloc_node_noprof+0x2bf/0x8d0 mm/slub.c:5663
 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline]
 nvme_pci_alloc_dev drivers/nvme/host/pci.c:3479 [inline]
 nvme_probe+0x2f1/0x1820 drivers/nvme/host/pci.c:3534
 local_pci_probe+0xef/0x1c0 drivers/pci/pci-driver.c:324
 pci_call_probe drivers/pci/pci-driver.c:392 [inline]
 __pci_device_probe drivers/pci/pci-driver.c:417 [inline]
 pci_device_probe+0x743/0x920 drivers/pci/pci-driver.c:451
 call_driver_probe drivers/base/dd.c:583 [inline]
 really_probe+0x29b/0xb70 drivers/base/dd.c:661
 __driver_probe_device+0x3b0/0x4a0 drivers/base/dd.c:803
 driver_probe_device+0x56/0x1f0 drivers/base/dd.c:833
 __driver_attach_async_helper+0x155/0x340 drivers/base/dd.c:1159
 async_run_entry_fn+0xa6/0x4b0 kernel/async.c:129
 process_one_work+0x956/0x1aa0 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x65c/0xe60 kernel/workqueue.c:3421
 kthread+0x41a/0x930 kernel/kthread.c:463
 ret_from_fork+0x6f8/0x8c0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff88800592a000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 244 bytes to the right of
 allocated 1152-byte region [ffff88800592a000, ffff88800592a480)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5928
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfffffc0000040(head|node=0|zone=1|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 000fffffc0000040 ffff888001042000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 000fffffc0000040 ffff888001042000 00000
---truncated---

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-43449?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43449?

Apply the vendor's patch.

## Is CVE-2026-43449 being exploited?

There is no known exploitation of CVE-2026-43449 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43449 and fix it if it is affected.

What it is: CVE-2026-43449 is a high-severity memory corruption vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-43449 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43449/ (Markdown: https://insights.sbomify.com/CVE-2026-43449/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43449
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43449
- OSV: https://osv.dev/vulnerability/CVE-2026-43449

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43449/
Summaries are generated and may contain mistakes; the official description above is the record.