---
id: CVE-2026-53363
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()

  iptfs_consume_frags() transfers paged fragments from one socket buffer
  to another but fails to propag…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()

  iptfs_consume_frags() transfers paged fragments from one socket buffer
  to another but fails to propag…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
published: '2026-07-10'
updated: '2026-07-18'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53363'
references:
  - url: 'https://git.kernel.org/stable/c/c885d111ed9f5a0a1f3cc4e87a50db6518abaa6c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dd66f7f6e360ee82cd905517726f8e9091265de5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e9096a5a170e7ecd6467bc2e08668ec39897cda7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00411
epssPercentile: 0.35136
ingestedAt: '2026-07-18T13:23:33.322Z'
---

## Overview

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

xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()

iptfs_consume_frags() transfers paged fragments from one socket buffer
to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is
the same class of bug that was fixed in skb_try_coalesce() for
CVE-2026-46300: when fragments backed by read-only page-cache pages are
merged, the marker indicating their shared nature must be preserved so
that ESP can decide correctly whether in-place encryption is safe.

Apply the same two-line fix used in skb_try_coalesce() to
iptfs_consume_frags().

## Remediation

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