What is CVE-2026-53236?

CVE-2026-53236 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 2.6.12 onward and patched in 6.1.176, 6.6.143, 6.12.94 and others. CVE-2026-53236 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-53236?

CVE-2026-53236 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-53236?

Yes, CVE-2026-53236 has been patched. Fixed versions include 6.1.176, 6.6.143, 6.12.94 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-53236 actively exploited?

CVE-2026-53236 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-53236

Medium

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.

Package Linux Kernel

Published 2026-06-25

Last modified 2026-07-08

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 2.6.12 and later are affected. Fixed in 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1 and their respective stable series.

Affected from

≥ 2.6.12

Fixed in

✓ 6.1.176 6.1.x ✓ 6.6.143 6.6.x ✓ 6.12.94 6.12.x ✓ 6.18.36 6.18.x ✓ 7.0.13 7.0.x ✓ 7.1

References

6 total

Kernel Git
https://git.kernel.org/stable/c/3747de241a66ef2c7032d2cc2b826a47c5fa0f6a

Patch
Kernel Git
https://git.kernel.org/stable/c/5d39580f68e6ddeedd15e587282207489dfb3da2

Patch
Kernel Git
https://git.kernel.org/stable/c/82b3e7ce10c53fc12aab8904745603efc74f8c07

Patch
Kernel Git
https://git.kernel.org/stable/c/c68517a3e18e20997808821c5559d0cba4d776c1

Patch
Kernel Git
https://git.kernel.org/stable/c/ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba

Patch

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-53236

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-06-25

Modified 2026-07-08

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-53236?

CVE-2026-53236 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.12 onward and has been patched in 6.1.176, 6.6.143, 6.12.94 and others. CVE-2026-53236 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-53236?

CVE-2026-53236 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-53236?

Yes. CVE-2026-53236 has been patched. Fixed versions include 6.1.176, 6.6.143, 6.12.94 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-53236 actively exploited?

No. CVE-2026-53236 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.