---
id: CVE-2025-39718
title: 'vsock/virtio: Validate length in packet header before skb_put()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vsock/virtio: Validate length in packet header before skb_put()

  When receiving a vsock packet in the guest, only the virtqueue buffer
  size is validated prior to virtio…
severity: high
cvss: 8.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= baddcc2c71572968cdaeee1c4ab3dc0ad90fa765 <
    969b06bd8b7560efb100a34227619e7d318fbe05
  - >-
    Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 <
    ee438c492b2e0705d819ac0e25d04fae758d8f8f
  - >-
    Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 <
    faf332a10372390ce65d0b803888f4b25a388335
  - >-
    Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 <
    676f03760ca1d69c2470cef36c44dc152494b47c
  - >-
    Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 <
    0dab92484474587b82e8e0455839eaf5ac7bf894
  - Linux >= 6.1.63 < 6.1.149
  - Linux 6.3
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:53:42.566432Z'
published: '2025-09-05'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:02:30.928Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-39718'
references:
  - url: 'https://git.kernel.org/stable/c/969b06bd8b7560efb100a34227619e7d318fbe05'
  - url: 'https://git.kernel.org/stable/c/ee438c492b2e0705d819ac0e25d04fae758d8f8f'
  - url: 'https://git.kernel.org/stable/c/faf332a10372390ce65d0b803888f4b25a388335'
  - url: 'https://git.kernel.org/stable/c/676f03760ca1d69c2470cef36c44dc152494b47c'
  - url: 'https://git.kernel.org/stable/c/0dab92484474587b82e8e0455839eaf5ac7bf894'
tags:
  - cve.org
epss: 0.00161
epssPercentile: 0.0523
ingestedAt: '2026-10-15T22:48:25.521Z'
---

## Overview

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

vsock/virtio: Validate length in packet header before skb_put()

When receiving a vsock packet in the guest, only the virtqueue buffer
size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately,
virtio_vsock_skb_rx_put() uses the length from the packet header as the
length argument to skb_put(), potentially resulting in SKB overflow if
the host has gone wonky.

Validate the length as advertised by the packet header before calling
virtio_vsock_skb_rx_put().

## Affected

- `Linux >= baddcc2c71572968cdaeee1c4ab3dc0ad90fa765 < 969b06bd8b7560efb100a34227619e7d318fbe05`
- `Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 < ee438c492b2e0705d819ac0e25d04fae758d8f8f`
- `Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 < faf332a10372390ce65d0b803888f4b25a388335`
- `Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 < 676f03760ca1d69c2470cef36c44dc152494b47c`
- `Linux >= 71dc9ec9ac7d3eee785cdc986c3daeb821381e20 < 0dab92484474587b82e8e0455839eaf5ac7bf894`
- `Linux >= 6.1.63 < 6.1.149`
- `Linux 6.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.