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

tcp: restrict SO_ATTACH_FILTER to priv users

This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets
to users with CAP_NET_ADMIN capability.

This blocks potential side-channel attack where an unprivileged application
attaches a filter to leak TCP sequence/acknowledgment numbers.

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4665-1 linux security update
Debian DLA Debian DLA DLA-4671-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-8726-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8727-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8728-1 Linux kernel (GCP) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 08 Sep 2026 09:30:00 +0000

Type Values Removed Values Added
References

Fri, 26 Jun 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-266
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Thu, 25 Jun 2026 09:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.
Title tcp: restrict SO_ATTACH_FILTER to priv users
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-08T08:50:07.534Z

Reserved: 2026-06-09T07:44:35.393Z

Link: CVE-2026-53236

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2026-06-25T09:16:41.493

Modified: 2026-09-08T09:18:14.913

Link: CVE-2026-53236

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-06-25T00:00:00Z

Links: CVE-2026-53236 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-12T09:30:01Z

Weaknesses