# CVE-2026-97989: vduse: validate virtqueue alignment

CVE-2026-97989 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-97989, released October 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-97989
- Priority: Routine
- CVSS: 5.5 (Moderate)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97989

## Description

In the Linux kernel, the following vulnerability has been resolved:  vduse: validate virtqueue alignment  vduse_validate_config() only checks the upper bound of vq_align. Invalid values can therefore reach vring_create_virtqueue_map(). The split-ring helpers use align - 1 as a bit mask, so the alignment must be a non-zero power of two. A zero value makes vring_size() drop the descriptor and available-ring part and vring_init() leave the used ring pointer NULL.  The VIRTIO spec requires the used ring to start at an address aligned to at least 4 bytes. Reject values below VRING_USED_ALIGN_SIZE as well as non-power-of-two values before they reach the virtio ring helpers.  Opening a virtio-net device created with vq_align=0 triggered:  BUG: KASAN: null-ptr-deref in virtqueue_kick_prepare_split+0xe3/0x100 Read of size 2 at addr 0000000000000000 by task systemd-network/1062  Call Trace (relevant frames):  dump_stack_lvl  print_report  kasan_report  __asan_load2  virtqueue_kick_prepare_split+0xe3/0x100  virtqueue_kick_prepare+0x40/0x60  try_fill_recv+0x857/0x1250  virtnet_open+0x189/0x460  __dev_open+0x225/0x390  __dev_change_flags+0x368/0x3b0  netif_change_flags+0x56/0xc0  do_setlink.isra.0+0x68c/0x1e30  Validate the value before it reaches the virtio ring helpers.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-97989](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97989.md) | Oct 2, 2026 |
| Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-97989](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97989.md) | Oct 2, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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