---
id: CVE-2026-31663
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm: hold dev ref until after transport_finish NF_HOOK

  After async crypto completes, xfrm_input_resume() calls dev_put()
  immediately on re-entry before the skb reache…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm: hold dev ref until after transport_finish NF_HOOK

  After async crypto completes, xfrm_input_resume() calls dev_put()
  immediately on re-entry before the skb reache…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-826
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.2.100, < 3.3'
  - 'linux_kernel >= 3.16.55, < 3.17'
  - 'linux_kernel >= 4.14.24, < 4.15'
  - 'linux_kernel >= 4.15.1, < 6.18.23'
  - 'linux_kernel >= 6.19, < 6.19.13'
  - linux_kernel = 4.15
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.13
published: '2026-04-24'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T13:17:45.590'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31663'
references:
  - url: 'https://git.kernel.org/stable/c/0f451b43c88bf2b9c038b414be580efee42e031b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1c428b03840094410c5fb6a5db30640486bbbfcb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4236c30b437b80f673b9e08c8fae38b8d471ac9e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5002beda5cac69d522dc54da0d5d463ed9c963d2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://access.redhat.com/errata/RHSA-2026:67471'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:68531'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:68532'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:68570'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-31663'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2461462'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31663.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-31663'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31663'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026042404-CVE-2026-31663-164c@gregkh/T
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00133
epssPercentile: 0.02294
scores:
  nvd: 7.8
  vendor: 7
  cna: 7.8
ingestedAt: '2026-08-06T13:59:37.031Z'
---

## Overview

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

xfrm: hold dev ref until after transport_finish NF_HOOK

After async crypto completes, xfrm_input_resume() calls dev_put()
immediately on re-entry before the skb reaches transport_finish.
The skb->dev pointer is then used inside NF_HOOK and its okfn,
which can race with device teardown.

Remove the dev_put from the async resumption entry and instead
drop the reference after the NF_HOOK call in transport_finish,
using a saved device pointer since NF_HOOK may consume the skb.
This covers NF_DROP, NF_QUEUE and NF_STOLEN paths that skip
the okfn.

For non-transport exits (decaps, gro, drop) and secondary
async return points, release the reference inline when
async is set.

## Affected

- `linux_kernel >= 3.2.100, < 3.3`
- `linux_kernel >= 3.16.55, < 3.17`
- `linux_kernel >= 4.14.24, < 4.15`
- `linux_kernel >= 4.15.1, < 6.18.23`
- `linux_kernel >= 6.19, < 6.19.13`
- `linux_kernel = 4.15`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.13`

## Vendor advisories

- **RHSA-2026:67471** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67471)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 7 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31663.json)
- **RHSA-2026:68570** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68570)
- **RHSA-2026:68531** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68531)
- **RHSA-2026:68532** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68532)