What is CVE-2026-23247?

CVE-2026-23247 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 4.10.14 onward and patched in 6.18.17, 6.19.7 and 7.0. CVE-2026-23247 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-23247?

CVE-2026-23247 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-2026-23247?

Yes, CVE-2026-23247 has been patched. Fixed versions include 6.18.17, 6.19.7 and 7.0. If you are running Linux kernel 4.10.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-23247 actively exploited?

CVE-2026-23247 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-23247

Medium

In the Linux kernel, the following vulnerability has been resolved: tcp: secure_seq: add back ports to TS offset This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.

Package Linux Kernel

Published 2026-03-18

Last modified 2026-05-21

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 4.10.14, 4.11 and later are affected. Fixed in 6.18.17, 6.19.7, 7.0 and their respective stable series.

Affected from

≥ 4.10.14 ≥ 4.11

Fixed in

✓ 6.18.17 6.18.x ✓ 6.19.7 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-23247 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1
Patch
Kernel patch commit
https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf
Patch
Kernel patch commit
https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805
Patch

Details

CVE ID CVE-2026-23247

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-03-18

Modified 2026-05-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-23247?

CVE-2026-23247 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.10.14 onward and has been patched in 6.18.17, 6.19.7 and 7.0. CVE-2026-23247 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-23247?

CVE-2026-23247 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-2026-23247?

Yes — CVE-2026-23247 has been patched. Fixed versions include 6.18.17, 6.19.7 and 7.0. If you are running Linux kernel 4.10.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-23247 actively exploited?

No — CVE-2026-23247 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.