Linux: Out-of-bounds Read
CVE-2026-43449 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 2b9d605c3f0d3262142f196249cd3bd58c857c71, 86183d550559e45e07059bbdf17331fea469e38c, d7990c936e25f484b61a5adeeadc1d290a9fd16e as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 2b9d605c3f0d3262142f196249cd3bd58c857c71 or 86183d550559e45e07059bbdf17331fea469e38c or d7990c936e25f484b61a5adeeadc1d290a9fd16e or 83e6edd6358326c9c2de31a54bb4a1ec50703f1f, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.15 or 4.20 or 5.5 or 5.10, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 2b9d605c3f0d3262142f196249cd3bd58c857c71; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 86183d550559e45e07059bbdf17331fea469e38c; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, d7990c936e25f484b61a5adeeadc1d290a9fd16e; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 83e6edd6358326c9c2de31a54bb4a1ec50703f1f; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 50bad78f03a02d3c0f228edf9912b494d3e7acb9; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 328c551f0cc81ee776b186b86cc6e5253bb6fda7; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, 78279d2d74c58a0ed64e43cf601a02649771182e; 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf up to, but not including, b4e78f1427c7d6859229ae9616df54e1fc05a516; and 9 more ranges | 2b9d605c3f0d3262142f196249cd3bd58c857c71, 86183d550559e45e07059bbdf17331fea469e38c, d7990c936e25f484b61a5adeeadc1d290a9fd16e, 83e6edd6358326c9c2de31a54bb4a1ec50703f1f, 50bad78f03a02d3c0f228edf9912b494d3e7acb9, 328c551f0cc81ee776b186b86cc6e5253bb6fda7 |
| Linux | Linux Kernel | 4.14.210 up to, but not including, 4.15; 4.19.161 up to, but not including, 4.20; 5.4.81 up to, but not including, 5.5; 5.9.12 up to, but not including, 5.10; 5.10.1 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.167; 6.2 up to, but not including, 6.6.130; and 5 more ranges | 4.15, 4.20, 5.5, 5.10, 5.10.253, 5.15.203 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
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---
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/2b9d605c3f0d3262142f196249cd3bd58c857c71
- git.kernel.org/stable/c/328c551f0cc81ee776b186b86cc6e5253bb6fda7
- git.kernel.org/stable/c/50bad78f03a02d3c0f228edf9912b494d3e7acb9
- git.kernel.org/stable/c/78279d2d74c58a0ed64e43cf601a02649771182e
- git.kernel.org/stable/c/83e6edd6358326c9c2de31a54bb4a1ec50703f1f
- git.kernel.org/stable/c/86183d550559e45e07059bbdf17331fea469e38c
- git.kernel.org/stable/c/b4e78f1427c7d6859229ae9616df54e1fc05a516
- git.kernel.org/stable/c/d7990c936e25f484b61a5adeeadc1d290a9fd16e
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 8.2 High severity
- 7.1 High severity
- 7.1 High severity
- 9.1 Critical severity
- 9.1 Critical severity
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