Description
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().
Published: 2026-07-10
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

iptfs_consume_frags() is a Linux kernel function that copies packet fragments from one socket buffer to another, but it does not propagate the SKBFL_SHARED_FRAG flag that marks fragments backed by read‑only page‑cache pages. When the ESP subsystem later attempts in‑place encryption, it uses this flag to decide whether the data can safely be lost the data is not shared and may proceed with encryption, potentially corrupting or exposing sensitive packet payloads. This improper handling can therefore lead to data corruption and confidentiality loss for ESP traffic.

Affected Systems

All Linux kernel configurations that include the xfrm/iptfs code path but have not applied the patch are affected. The vulnerability applies to any kernel build that contains the iptfs_consume_frags() path prior to the commit that added the two‑line fix (c885d111ed9f5a0a1f3cc4e87a50db6518abaa6c). No specific kernel release numbers are listed, so any kernel version lacking this commit may be vulnerable.

Risk and Exploitability

EPSS score is less than 1% and the vulnerability is not listed in CISA's KEV not provided. The likely attack vector is exploiting fragmented traffic handled by the ESP subsystem. Based on the description, it is inferred that an attacker would need to influence or observe ESP‑fragmented traffic, which typically requires local With considered low to moderate until further evidence or exploit availability emerges.

Generated by OpenCVE AI on July 28, 2026 at 08:19 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the system to a Linux kernel version that includes the patch for CVE‑2026‑53363.
  • If upgrading is not immediately possible, backport the two‑line patch that preserves the SKBFL_SHARED_FRAG flag into the running kernel and rebuild the kernel.
  • Test ESP fragmentation handling to confirm that in‑place encryption behaves correctly, for example by capturing traffic with packet fragments and verifying the presence of proper encryption markers.

Generated by OpenCVE AI on July 28, 2026 at 08:19 UTC.

Tracking

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Advisories

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History

Sat, 18 Jul 2026 08:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Sat, 11 Jul 2026 00:15:00 +0000


Fri, 10 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Description 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().
Title xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-18T07:33:32.898Z

Reserved: 2026-06-09T07:44:35.400Z

Link: CVE-2026-53363

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity :

Publid Date: 2026-07-10T00:00:00Z

Links: CVE-2026-53363 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-28T08:30:18Z

Weaknesses
  • CWE-821

    Incorrect Synchronization