What is CVE-2026-23254?

CVE-2026-23254 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.6.31 onward and patched in 6.6.124, 6.12.70, 6.18.10 and others. CVE-2026-23254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-23254?

CVE-2026-23254 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-2026-23254?

Yes, CVE-2026-23254 has been patched. Fixed versions include 6.6.124, 6.12.70, 6.18.10 and others. If you are running Linux kernel 6.6.31 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-23254 actively exploited?

CVE-2026-23254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-23254

Medium

In the Linux kernel, the following vulnerability has been resolved: net: gro: fix outer network offset The udp GRO complete stage assumes that all the packets inserted the RX have the `encapsulation` flag zeroed. Such assumption is not true, as a few H/W NICs can set such flag when H/W offloading the checksum for an UDP encapsulated traffic, the tun driver can inject GSO packets with UDP encapsulation and the problematic layout can also be created via a veth based setup. Due to the above, in the problematic scenarios, udp4_gro_complete() uses the wrong network offset (inner instead of outer) to compute the outer UDP header pseudo checksum, leading to csum validation errors later on in packet processing. Address the issue always clearing the encapsulation flag at GRO completion time. Such flag will be set again as needed for encapsulated packets by udp_gro_complete().

Package Linux Kernel

Published 2026-03-18

Last modified 2026-06-01

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 6.6.31, 6.8.10, 6.9 and later are affected. Fixed in 6.6.124, 6.12.70, 6.18.10, 6.19 and their respective stable series.

Affected from

≥ 6.6.31 ≥ 6.8.10 ≥ 6.9

Fixed in

✓ 6.6.124 6.6.x ✓ 6.12.70 6.12.x ✓ 6.18.10 6.18.x ✓ 6.19

References

4 total

Kernel Git
https://git.kernel.org/stable/c/2e5edb69e5d0e23ef248c56fc977039268c77a7b

Patch
Kernel Git
https://git.kernel.org/stable/c/5c2c3c38be396257a6a2e55bd601a12bb9781507

Patch
Kernel Git
https://git.kernel.org/stable/c/9d40a85138568696387ef04cd004c64612a70874

Patch
Kernel Git
https://git.kernel.org/stable/c/b83557bc6f560433fe5d727e241069f8db5ba709

Patch

Details

CVE ID CVE-2026-23254

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-03-18

Modified 2026-06-01

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-23254?

CVE-2026-23254 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.6.31 onward and has been patched in 6.6.124, 6.12.70, 6.18.10 and others. CVE-2026-23254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-23254?

CVE-2026-23254 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-2026-23254?

Yes. CVE-2026-23254 has been patched. Fixed versions include 6.6.124, 6.12.70, 6.18.10 and others. If you are running Linux kernel 6.6.31 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-23254 actively exploited?

No. CVE-2026-23254 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.